Merge architect's per-file test detail into the checkpoint doc fix

Architect independently reclaimed this task after my fix landed and
rewrote the same doc with more precise per-file test descriptions and a
more specific gap list -- genuinely better in places (caught real detail
I'd summarized loosely) but its own investigation also introduced one
factual error (claimed 18 tests in test_auth_age_gate.py; verified via
pytest --collect-only, it's 17) and dropped two things worth keeping:
the exact commit hash for reproducibility, and the Client export section
(it never looked at the export step).

Merged: kept the architect's richer per-file coverage descriptions and
gap analysis, restored the verified counts/commit hash/export section/
--quit gotcha from my original.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitignore

@@ -1,4 +1,4 @@
-# Godot editor cache / generated files
+# Godot 4 editor cache/import directory
 .godot/
 
 # Godot export artifacts
@@ -8,3 +8,6 @@ export/
 # OS
 .DS_Store
 Thumbs.db
+
+# Godot UID files (regenerated from path)
+*.uid

backend/.env.example

@@ -0,0 +1,23 @@
+# Database (async driver)
+DATABASE_URL=postgresql+asyncpg://agp_user:agp_password@localhost:5432/agp_db
+
+# Redis
+REDIS_URL=redis://localhost:6379/0
+
+# JWT / Auth
+ALGORITHM=RS256
+ACCESS_TOKEN_EXPIRE_MINUTES=60
+REFRESH_TOKEN_EXPIRE_DAYS=30
+# Directory where the RSA keypair is loaded/generated at runtime.
+# Defaults to ~/.agp/keys (outside the repo). Keys are never committed to git.
+RSA_KEY_DIR=~/.agp/keys
+
+# App
+APP_NAME=AGP Backend
+APP_VERSION=0.1.0
+DEBUG=true
+CORS_ORIGINS=http://localhost:8080,http://localhost:3000
+
+# File uploads
+UPLOAD_DIR=uploads
+MAX_UPLOAD_SIZE_MB=100

backend/.gitignore

@@ -0,0 +1,4 @@
+.env
+__pycache__/
+*.pyc
+.venv/

backend/alembic.ini

@@ -0,0 +1,42 @@
+# Alembic configuration file.
+# Run: alembic upgrade head  (to apply migrations)
+# Run: alembic revision --autogenerate -m "description"  (to generate migration)
+
+[alembic]
+script_location = alembic
+prepend_sys_path = .
+sqlalchemy.url = postgresql+asyncpg://agp_user:agp_password@localhost:5432/agp_db
+
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

backend/alembic/env.py

@@ -0,0 +1,65 @@
+"""Alembic environment configuration."""
+
+import asyncio
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy.ext.asyncio import create_async_engine
+
+from app.config import settings
+from app.database import Base
+from app.models import user, session, world, asset  # noqa: F401
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    """Run migrations in 'offline' mode."""
+    url = settings.DATABASE_URL
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def do_run_migrations(connection):
+    context.configure(connection=connection, target_metadata=target_metadata)
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+async def run_async_migrations():
+    """Run migrations in 'online' mode with async engine."""
+    connectable = create_async_engine(settings.DATABASE_URL, echo=False)
+
+    async with connectable.connect() as connection:
+        await connection.run_sync(do_run_migrations)
+
+    await connectable.dispose()
+
+
+def run_migrations_online() -> None:
+    """Run migrations in 'online' mode."""
+    asyncio.run(run_async_migrations())
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

backend/alembic/script.py.mako

@@ -0,0 +1,27 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision: str = ${repr(up_revision)}
+down_revision: Union[str, None] = ${repr(down_revision)}
+branch_labels: Union[str, Sequence[str], None] = ${repr(branch_labels)}
+depends_on: Union[str, Sequence[str], None] = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    """Upgrade database schema."""
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    """Downgrade database schema."""
+    ${downgrades if downgrades else "pass"}

backend/alembic/versions/0001_initial.py

@@ -0,0 +1,127 @@
+"""initial schema
+
+Revision ID: 0001_initial
+Revises:
+Create Date: 2024-01-01 00:00:00.000000
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision: str = "0001_initial"
+down_revision: Union[str, None] = None
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade database schema."""
+    # Create ENUM types
+    world_visibility = postgresql.ENUM(
+        "public", "private", "friends_only", name="world_visibility"
+    )
+    world_visibility.create(op.get_bind(), checkfirst=True)
+
+    asset_type = postgresql.ENUM(
+        "image", "audio", "video", "document", "model_3d", "other", name="asset_type"
+    )
+    asset_type.create(op.get_bind(), checkfirst=True)
+
+    # Create users table
+    op.create_table(
+        "users",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column("username", sa.String(length=50), nullable=False),
+        sa.Column("email", sa.String(length=120), nullable=False),
+        sa.Column("hashed_password", sa.String(length=255), nullable=False),
+        sa.Column("is_active", sa.Boolean(), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now()),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=True),
+    )
+    op.create_index(op.f("ix_users_email"), "users", ["email"], unique=True)
+    op.create_index(op.f("ix_users_id"), "users", ["id"], unique=False)
+    op.create_index(op.f("ix_users_username"), "users", ["username"], unique=True)
+
+    # Create sessions table
+    op.create_table(
+        "sessions",
+        sa.Column("id", sa.String(length=36), primary_key=True),
+        sa.Column("user_id", sa.Integer(), nullable=False),
+        sa.Column("token", sa.String(), nullable=False),
+        sa.Column("expires_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("is_active", sa.Boolean(), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now()),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now()),
+        sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="CASCADE"),
+    )
+    op.create_index(op.f("ix_sessions_token"), "sessions", ["token"], unique=True)
+
+    # Create worlds table
+    op.create_table(
+        "worlds",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column("name", sa.String(length=255), nullable=False),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column("owner_id", sa.Integer(), nullable=False),
+        sa.Column(
+            "visibility",
+            postgresql.ENUM(
+                "public", "private", "friends_only", name="world_visibility",
+                create_type=False,
+            ),
+            nullable=True,
+        ),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now()),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=True),
+        sa.ForeignKeyConstraint(["owner_id"], ["users.id"]),
+    )
+    op.create_index(op.f("ix_worlds_id"), "worlds", ["id"], unique=False)
+
+    # Create assets table
+    op.create_table(
+        "assets",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column("name", sa.String(length=255), nullable=False),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column(
+            "asset_type",
+            postgresql.ENUM(
+                "image", "audio", "video", "document", "model_3d", "other",
+                name="asset_type", create_type=False,
+            ),
+            nullable=False,
+        ),
+        sa.Column("file_path", sa.String(length=512), nullable=False),
+        sa.Column("file_size", sa.Integer(), nullable=True),
+        sa.Column("mime_type", sa.String(length=128), nullable=True),
+        sa.Column("metadata_json", sa.Text(), nullable=True),
+        sa.Column("world_id", sa.Integer(), nullable=True),
+        sa.Column("owner_id", sa.Integer(), nullable=False),
+        sa.Column("is_public", sa.Boolean(), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now()),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now()),
+        sa.ForeignKeyConstraint(["owner_id"], ["users.id"]),
+        sa.ForeignKeyConstraint(["world_id"], ["worlds.id"]),
+    )
+    op.create_index(op.f("ix_assets_id"), "assets", ["id"], unique=False)
+
+
+def downgrade() -> None:
+    """Downgrade database schema."""
+    op.drop_index(op.f("ix_assets_id"), table_name="assets")
+    op.drop_table("assets")
+    op.drop_index(op.f("ix_worlds_id"), table_name="worlds")
+    op.drop_table("worlds")
+    op.drop_index(op.f("ix_sessions_token"), table_name="sessions")
+    op.drop_table("sessions")
+    op.drop_index(op.f("ix_users_username"), table_name="users")
+    op.drop_index(op.f("ix_users_id"), table_name="users")
+    op.drop_index(op.f("ix_users_email"), table_name="users")
+    op.drop_table("users")
+
+    # Drop ENUM types
+    postgresql.ENUM(name="asset_type").drop(op.get_bind(), checkfirst=True)
+    postgresql.ENUM(name="world_visibility").drop(op.get_bind(), checkfirst=True)

backend/alembic/versions/0002_add_date_of_birth_to_users.py

@@ -0,0 +1,30 @@
+"""add date_of_birth column to users table
+
+Revision ID: 0002_add_date_of_birth_to_users
+Revises: 0001_initial
+Create Date: 2025-01-01 00:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision: str = "0002_add_date_of_birth_to_users"
+down_revision: Union[str, None] = "0001_initial"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Add date_of_birth column to users table."""
+    op.add_column(
+        "users",
+        sa.Column("date_of_birth", sa.Date(), nullable=True),
+    )
+
+
+def downgrade() -> None:
+    """Remove date_of_birth column from users table."""
+    op.drop_column("users", "date_of_birth")

backend/alembic/versions/0003_add_refresh_tokens_table.py

@@ -0,0 +1,36 @@
+"""add refresh_tokens table
+
+Revision ID: 0003_add_refresh_tokens_table
+Revises: 0002_add_date_of_birth_to_users
+Create Date: 2025-07-25 00:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision: str = "0003_add_refresh_tokens_table"
+down_revision: Union[str, None] = "0002_add_date_of_birth_to_users"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Create the refresh_tokens table."""
+    op.create_table(
+        "refresh_tokens",
+        sa.Column("id", sa.String(36), primary_key=True),
+        sa.Column("user_id", sa.Integer(), sa.ForeignKey("users.id", ondelete="CASCADE"), nullable=False),
+        sa.Column("token", sa.String(512), unique=True, index=True, nullable=False),
+        sa.Column("expires_at", sa.DateTime(timezone=True), nullable=False),
+        sa.Column("is_active", sa.Boolean(), server_default=sa.text("true"), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+    )
+
+
+def downgrade() -> None:
+    """Drop the refresh_tokens table."""
+    op.drop_table("refresh_tokens")

backend/app/config.py

@@ -0,0 +1,127 @@
+"""Application configuration via pydantic-settings."""
+
+from functools import lru_cache
+from pathlib import Path
+
+from cryptography.hazmat.primitives.asymmetric.rsa import (
+    RSAPrivateKey,
+    RSAPublicKey,
+    generate_private_key,
+)
+from cryptography.hazmat.primitives.serialization import (
+    Encoding,
+    NoEncryption,
+    PrivateFormat,
+    PublicFormat,
+    load_pem_private_key,
+    load_pem_public_key,
+)
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+
+def _load_or_generate_rsa_keys(key_dir: Path) -> tuple[bytes, bytes]:
+    """Load existing RSA keys or generate a new pair.
+
+    Keys are stored as PEM files in *key_dir*.  The directory is created
+    if it does not exist.  Files are named ``private.pem`` and
+    ``public.pem`` and are **not** committed to git.
+    """
+    private_path = key_dir / "private.pem"
+    public_path = key_dir / "public.pem"
+
+    if private_path.exists() and public_path.exists():
+        private_pem = private_path.read_bytes()
+        public_pem = public_path.read_bytes()
+    else:
+        # Generate a new 2048-bit RSA key pair
+        private_key = generate_private_key(public_exponent=65537, key_size=2048)
+        private_pem = private_key.private_bytes(
+            Encoding.PEM,
+            PrivateFormat.PKCS8,
+            NoEncryption(),
+        )
+        public_pem = private_key.public_key().public_bytes(
+            Encoding.PEM,
+            PublicFormat.SubjectPublicKeyInfo,
+        )
+        key_dir.mkdir(parents=True, exist_ok=True)
+        private_path.write_bytes(private_pem)
+        public_path.write_bytes(public_pem)
+
+    return private_pem, public_pem
+
+
+class Settings(BaseSettings):
+    # App
+    APP_NAME: str = "AGP Backend"
+    APP_VERSION: str = "0.1.0"
+    DEBUG: bool = True
+
+    # Database (async)
+    DATABASE_URL: str = "postgresql+asyncpg://agp_user:agp_password@localhost:5432/agp_db"
+
+    # Redis
+    REDIS_URL: str = "redis://localhost:6379/0"
+
+    # JWT / Auth
+    ALGORITHM: str = "RS256"
+    ACCESS_TOKEN_EXPIRE_MINUTES: int = 60
+    REFRESH_TOKEN_EXPIRE_DAYS: int = 30
+
+    # RS256 key storage.  Defaults to a directory outside the repo so the
+    # generated keypair is never accidentally committed.
+    RSA_KEY_DIR: str = str(Path.home() / ".agp" / "keys")
+
+    # CORS
+    CORS_ORIGINS: str = "http://localhost:8080,http://localhost:3000"
+
+    # File uploads
+    UPLOAD_DIR: str = "uploads"
+    MAX_UPLOAD_SIZE_MB: int = 100
+    GLTF_MAX_FILE_SIZE_MB: int = 200
+
+    model_config = SettingsConfigDict(
+        env_file=".env",
+        env_file_encoding="utf-8",
+        case_sensitive=True,
+    )
+
+    @property
+    def cors_origins_list(self) -> list[str]:
+        return [origin.strip() for origin in self.CORS_ORIGINS.split(",")]
+
+    @property
+    def rsa_key_dir(self) -> Path:
+        return Path(self.RSA_KEY_DIR)
+
+    @property
+    def private_pem(self) -> bytes:
+        """Return the private key PEM bytes (loads/generates on first call)."""
+        private_pem, _ = _load_or_generate_rsa_keys(self.rsa_key_dir)
+        return private_pem
+
+    @property
+    def public_pem(self) -> bytes:
+        """Return the public key PEM bytes (loads/generates on first call)."""
+        _, public_pem = _load_or_generate_rsa_keys(self.rsa_key_dir)
+        return public_pem
+
+    @property
+    def private_key(self) -> RSAPrivateKey:
+        """Return the deserialized RSA private key object."""
+        return load_pem_private_key(self.private_pem, password=None)
+
+    @property
+    def public_key(self) -> RSAPublicKey:
+        """Return the deserialized RSA public key object."""
+        return load_pem_public_key(self.public_pem)
+
+
+@lru_cache()
+def get_settings() -> Settings:
+    """Return cached settings instance."""
+    return Settings()
+
+
+# Convenience singleton
+settings = get_settings()

backend/app/database.py

@@ -0,0 +1,42 @@
+"""Async database engine and session factory."""
+
+from sqlalchemy.ext.asyncio import (
+    AsyncSession,
+    async_sessionmaker,
+    create_async_engine,
+)
+from sqlalchemy.orm import DeclarativeBase
+
+from app.config import settings
+
+engine = create_async_engine(
+    settings.DATABASE_URL,
+    echo=settings.DEBUG,
+    pool_size=10,
+    max_overflow=20,
+)
+
+async_session_factory = async_sessionmaker(
+    engine,
+    class_=AsyncSession,
+    expire_on_commit=False,
+)
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+async def get_db() -> AsyncSession:
+    """Dependency that yields an async database session.
+
+    Handlers are responsible for committing or rolling back their own
+    transactions.  This avoids the double-commit problem where the
+    session is committed both here and in the handler.
+    """
+    async with async_session_factory() as session:
+        try:
+            yield session
+        except Exception:
+            await session.rollback()
+            raise

backend/app/dependencies.py

@@ -0,0 +1,55 @@
+"""Shared FastAPI dependencies, including JWT-based auth."""
+
+from typing import Annotated
+
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from jose import JWTError, jwt
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.config import settings
+from app.database import get_db
+from app.models.user import User
+
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/auth/login")
+
+
+async def get_current_user(
+    token: Annotated[str, Depends(oauth2_scheme)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+) -> User:
+    """Resolve the JWT bearer token to a User, or raise 401."""
+    credentials_exception = HTTPException(
+        status_code=status.HTTP_401_UNAUTHORIZED,
+        detail="Could not validate credentials",
+        headers={"WWW-Authenticate": "Bearer"},
+    )
+    try:
+        payload = jwt.decode(
+            token, settings.public_pem, algorithms=[settings.ALGORITHM]
+        )
+        user_id: str | None = payload.get("sub")
+        if user_id is None:
+            raise credentials_exception
+    except JWTError:
+        raise credentials_exception
+
+    try:
+        user_id_int = int(user_id)
+    except (ValueError, TypeError):
+        raise credentials_exception
+
+    result = await db.execute(select(User).where(User.id == user_id_int))
+    user = result.scalar_one_or_none()
+    if user is None:
+        raise credentials_exception
+    if not user.is_active:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="User account is inactive",
+        )
+    return user
+
+
+CurrentUser = Annotated[User, Depends(get_current_user)]

backend/app/main.py

@@ -0,0 +1,46 @@
+"""FastAPI application entry point."""
+
+from contextlib import asynccontextmanager
+
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.config import settings
+from app.routers import auth, users, worlds, assets
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    """Application lifespan: startup and shutdown events."""
+    # Startup: initialize database, connect to Redis, etc.
+    yield
+    # Shutdown: close connections, cleanup
+
+
+app = FastAPI(
+    title=settings.APP_NAME,
+    version=settings.APP_VERSION,
+    description="Agentic Game Platform - Backend API",
+    lifespan=lifespan,
+)
+
+# CORS
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=settings.cors_origins_list,
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include routers
+app.include_router(auth.router, prefix="/api/auth", tags=["auth"])
+app.include_router(users.router, prefix="/api/users", tags=["users"])
+app.include_router(worlds.router, prefix="/api/worlds", tags=["worlds"])
+app.include_router(assets.router, prefix="/api/assets", tags=["assets"])
+
+
+@app.get("/api/health")
+async def health_check():
+    """Simple health check endpoint."""
+    return {"status": "ok", "app": settings.APP_NAME}

backend/app/models/__init__.py

@@ -0,0 +1,6 @@
+from app.models.user import User
+from app.models.session import Session
+from app.models.world import World
+from app.models.asset import Asset
+
+__all__ = ["User", "Session", "World", "Asset"]

backend/app/models/asset.py

@@ -0,0 +1,40 @@
+from sqlalchemy import Column, Integer, String, ForeignKey, Text, DateTime, Boolean
+from sqlalchemy.dialects.postgresql import ENUM
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+import enum
+
+from app.database import Base
+
+
+class AssetType(str, enum.Enum):
+    IMAGE = "image"
+    AUDIO = "audio"
+    VIDEO = "video"
+    DOCUMENT = "document"
+    MODEL_3D = "model_3d"
+    OTHER = "other"
+
+
+class Asset(Base):
+    __tablename__ = "assets"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String(255), nullable=False)
+    description = Column(Text, nullable=True)
+    asset_type = Column(
+        ENUM(AssetType, name="asset_type", create_type=False),
+        nullable=False,
+    )
+    file_path = Column(String(512), nullable=False)
+    file_size = Column(Integer, nullable=True)
+    mime_type = Column(String(128), nullable=True)
+    metadata_json = Column(Text, nullable=True)
+    world_id = Column(Integer, ForeignKey("worlds.id"), nullable=True)
+    owner_id = Column(Integer, ForeignKey("users.id"), nullable=False)
+    is_public = Column(Boolean, default=False, nullable=False)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now())
+
+    owner = relationship("User", back_populates="assets")
+    world = relationship("World", back_populates="assets")

backend/app/models/session.py

@@ -0,0 +1,41 @@
+import uuid
+
+from sqlalchemy import Column, Integer, String, DateTime, ForeignKey, Boolean
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from app.database import Base
+
+
+class Session(Base):
+    __tablename__ = "sessions"
+
+    id = Column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
+    user_id = Column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False)
+    token = Column(String, unique=True, index=True, nullable=False)
+    expires_at = Column(DateTime(timezone=True), nullable=False)
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now())
+
+    user = relationship("User", back_populates="sessions")
+
+
+class RefreshToken(Base):
+    __tablename__ = "refresh_tokens"
+
+    id = Column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
+    user_id = Column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False)
+    # RS256 JWTs are ~420+ chars; 512 is sufficient and matches the migration.
+    token = Column(String(512), unique=True, index=True, nullable=False)
+    expires_at = Column(DateTime(timezone=True), nullable=False)
+    is_active = Column(Boolean, nullable=False, default=True, server_default="true")
+    created_at = Column(DateTime(timezone=True), nullable=False, server_default=func.now())
+    updated_at = Column(
+        DateTime(timezone=True),
+        nullable=False,
+        server_default=func.now(),
+        onupdate=func.now(),
+    )
+
+    user = relationship("User", back_populates="refresh_tokens")

backend/app/models/user.py

@@ -0,0 +1,38 @@
+from datetime import date
+from typing import Optional
+
+from sqlalchemy import Column, Integer, String, Boolean, DateTime, Date
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from app.database import Base
+
+
+class User(Base):
+    __tablename__ = "users"
+
+    id = Column(Integer, primary_key=True, index=True)
+    username = Column(String(50), unique=True, index=True, nullable=False)
+    email = Column(String(120), unique=True, index=True, nullable=False)
+    hashed_password = Column(String(255), nullable=False)
+    date_of_birth = Column(Date, nullable=True)
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+
+    sessions = relationship("Session", back_populates="user", cascade="all, delete-orphan")
+    refresh_tokens = relationship("RefreshToken", back_populates="user", cascade="all, delete-orphan")
+    worlds = relationship("World", back_populates="owner")
+    assets = relationship("Asset", back_populates="owner")
+
+    @property
+    def is_adult(self) -> bool:
+        """Return True if the user is 18 or older based on date_of_birth."""
+        if self.date_of_birth is None:
+            return False
+        today = date.today()
+        age = today.year - self.date_of_birth.year
+        # Adjust if birthday hasn't occurred yet this year
+        if (today.month, today.day) < (self.date_of_birth.month, self.date_of_birth.day):
+            age -= 1
+        return age >= 18

backend/app/models/world.py

@@ -0,0 +1,36 @@
+from sqlalchemy import Column, Integer, String, Text, DateTime, ForeignKey
+from sqlalchemy.dialects.postgresql import ENUM
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+import enum
+
+from app.database import Base
+
+
+class WorldVisibility(enum.Enum):
+    PUBLIC = "public"
+    PRIVATE = "private"
+    FRIENDS_ONLY = "friends_only"
+
+
+class World(Base):
+    __tablename__ = "worlds"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String(255), nullable=False)
+    description = Column(Text, nullable=True)
+    owner_id = Column(Integer, ForeignKey("users.id"), nullable=False)
+    visibility = Column(
+        ENUM(
+            WorldVisibility,
+            name="world_visibility",
+            create_type=False,
+            values_callable=lambda enum_cls: [e.value for e in enum_cls],
+        ),
+        default=WorldVisibility.PUBLIC,
+    )
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+
+    owner = relationship("User", back_populates="worlds")
+    assets = relationship("Asset", back_populates="world", cascade="all, delete-orphan")

backend/app/routers/assets.py

@@ -0,0 +1,243 @@
+"""Asset management router."""
+
+import json
+import os
+from pathlib import Path
+from typing import Optional
+
+from fastapi import APIRouter, Depends, HTTPException, UploadFile, File, Query
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.config import settings
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.asset import Asset, AssetType
+from app.models.world import World
+from app.services import gltf as gltf_service
+from pydantic import BaseModel, Field
+
+router = APIRouter()
+
+
+# --- Pydantic schemas ---
+
+class AssetCreate(BaseModel):
+    """Schema for creating an asset reference."""
+    name: str = Field(..., min_length=1, max_length=255)
+    description: Optional[str] = None
+    asset_type: AssetType
+    world_id: Optional[int] = None
+
+
+class AssetResponse(BaseModel):
+    """Schema for asset responses."""
+    id: int
+    name: str
+    description: Optional[str]
+    asset_type: AssetType
+    file_path: str
+    file_size: Optional[int]
+    mime_type: Optional[str]
+    world_id: Optional[int]
+    owner_id: int
+    is_public: bool
+    created_at: str
+    updated_at: str
+
+    model_config = {"from_attributes": True}
+
+
+class AssetUpdate(BaseModel):
+    """Schema for updating an asset."""
+    name: Optional[str] = None
+    description: Optional[str] = None
+    is_public: Optional[bool] = None
+
+
+# --- Helpers ---
+
+def _sanitize_filename(filename: str) -> str:
+    """Strip path components and unsafe characters from a filename."""
+    # Remove any directory components (path traversal protection).
+    base = os.path.basename(filename.replace("\\", "/"))
+    # Keep only safe characters.
+    safe = "".join(c for c in base if c.isalnum() or c in "._-")
+    return safe or "file"
+
+
+def _detect_asset_type(filename: Optional[str], content: bytes) -> AssetType:
+    """Detect the asset type from filename and content."""
+    if filename and gltf_service.looks_like_gltf(content, filename):
+        return AssetType.MODEL_3D
+    # Fallback: let the caller decide based on mime_type or default.
+    return AssetType.OTHER
+
+
+# --- Endpoints ---
+
+@router.post("/", response_model=AssetResponse, status_code=201)
+async def create_asset(
+    payload: AssetCreate,
+    current_user: CurrentUser,
+    db: AsyncSession = Depends(get_db),
+):
+    """Create a new asset reference."""
+    # Verify world ownership if world_id is provided
+    if payload.world_id is not None:
+        world = await db.get(World, payload.world_id)
+        if world is None:
+            raise HTTPException(status_code=404, detail="World not found")
+        if world.owner_id != current_user.id:
+            raise HTTPException(status_code=403, detail="Not owner of this world")
+
+    asset = Asset(
+        name=payload.name,
+        description=payload.description,
+        asset_type=payload.asset_type,
+        file_path="",  # Will be set after upload
+        owner_id=current_user.id,
+        world_id=payload.world_id,
+        is_public=False,
+    )
+    db.add(asset)
+    await db.commit()
+    await db.refresh(asset)
+    return asset
+
+
+@router.get("/", response_model=list[AssetResponse])
+async def list_assets(
+    current_user: CurrentUser,
+    world_id: Optional[int] = Query(None, description="Filter by world"),
+    asset_type: Optional[AssetType] = Query(None),
+    limit: int = Query(50, ge=1, le=100),
+    offset: int = Query(0, ge=0),
+    db: AsyncSession = Depends(get_db),
+):
+    """List assets with optional filters."""
+    stmt = select(Asset).where(Asset.owner_id == current_user.id)
+
+    if world_id is not None:
+        stmt = stmt.where(Asset.world_id == world_id)
+    if asset_type is not None:
+        stmt = stmt.where(Asset.asset_type == asset_type)
+
+    stmt = stmt.order_by(Asset.created_at.desc()).limit(limit).offset(offset)
+    result = await db.execute(stmt)
+    assets = result.scalars().all()
+    return assets
+
+
+@router.get("/{asset_id}", response_model=AssetResponse)
+async def get_asset(
+    asset_id: int,
+    current_user: CurrentUser,
+    db: AsyncSession = Depends(get_db),
+):
+    """Get a single asset by ID."""
+    asset = await db.get(Asset, asset_id)
+    if asset is None or asset.owner_id != current_user.id:
+        raise HTTPException(status_code=404, detail="Asset not found")
+    return asset
+
+
+@router.patch("/{asset_id}", response_model=AssetResponse)
+async def update_asset(
+    asset_id: int,
+    payload: AssetUpdate,
+    current_user: CurrentUser,
+    db: AsyncSession = Depends(get_db),
+):
+    """Update an asset."""
+    asset = await db.get(Asset, asset_id)
+    if asset is None or asset.owner_id != current_user.id:
+        raise HTTPException(status_code=404, detail="Asset not found")
+
+    update_data = payload.model_dump(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(asset, field, value)
+
+    await db.commit()
+    await db.refresh(asset)
+    return asset
+
+
+@router.delete("/{asset_id}", status_code=204)
+async def delete_asset(
+    asset_id: int,
+    current_user: CurrentUser,
+    db: AsyncSession = Depends(get_db),
+):
+    """Delete an asset."""
+    asset = await db.get(Asset, asset_id)
+    if asset is None or asset.owner_id != current_user.id:
+        raise HTTPException(status_code=404, detail="Asset not found")
+
+    await db.delete(asset)
+    await db.commit()
+
+
+@router.post("/{asset_id}/upload", response_model=AssetResponse)
+async def upload_asset_file(
+    asset_id: int,
+    current_user: CurrentUser,
+    file: UploadFile = File(...),
+    db: AsyncSession = Depends(get_db),
+):
+    """Upload a file for an existing asset."""
+    asset = await db.get(Asset, asset_id)
+    if asset is None or asset.owner_id != current_user.id:
+        raise HTTPException(status_code=404, detail="Asset not found")
+
+    # Sanitize filename to prevent path traversal.
+    safe_filename = _sanitize_filename(file.filename or f"asset_{asset_id}")
+
+    # Read the file content.
+    content = await file.read()
+    file_size = len(content)
+
+    # Determine which size limit to apply.
+    if gltf_service.looks_like_gltf(content, file.filename):
+        max_bytes = settings.GLTF_MAX_FILE_SIZE_MB * 1024 * 1024
+    else:
+        max_bytes = settings.MAX_UPLOAD_SIZE_MB * 1024 * 1024
+
+    if file_size > max_bytes:
+        raise HTTPException(
+            status_code=413,
+            detail=f"File size {file_size} exceeds maximum allowed size {max_bytes} bytes",
+        )
+
+    # Write the file to the upload directory.
+    upload_dir = Path(settings.UPLOAD_DIR)
+    upload_dir.mkdir(parents=True, exist_ok=True)
+    stored_name = f"{asset_id}_{safe_filename}"
+    file_path = upload_dir / stored_name
+    file_path.write_bytes(content)
+
+    # Detect asset type from content/filename.
+    detected_type = _detect_asset_type(file.filename, content)
+
+    # Update asset record.
+    asset.file_path = str(file_path)
+    asset.mime_type = file.content_type
+    asset.file_size = file_size
+
+    # If this is a glTF file, extract and store metadata.
+    if detected_type == AssetType.MODEL_3D:
+        try:
+            metadata = gltf_service.extract_gltf_metadata(content)
+            asset.metadata_json = json.dumps(metadata)
+            # Also set the asset type to model_3d if it was auto-detected.
+            if asset.asset_type == AssetType.OTHER:
+                asset.asset_type = AssetType.MODEL_3D
+        except ValueError as exc:
+            raise HTTPException(
+                status_code=400,
+                detail=f"Invalid glTF file: {exc}",
+            )
+
+    await db.commit()
+    await db.refresh(asset)
+    return asset

backend/app/routers/auth.py

@@ -0,0 +1,315 @@
+"""Authentication router - login, register, token refresh."""
+
+import uuid
+from datetime import date, datetime, timedelta, timezone
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordRequestForm
+from jose import JWTError, jwt
+from passlib.context import CryptContext
+from pydantic import BaseModel, EmailStr, field_validator
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.config import settings
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.session import RefreshToken
+from app.models.user import User
+
+pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
+
+router = APIRouter()
+
+
+# --- Pydantic schemas ---
+
+class TokenResponse(BaseModel):
+    access_token: str
+    refresh_token: str
+    token_type: str = "bearer"
+    access_token_expires_minutes: int
+
+
+class RefreshRequest(BaseModel):
+    refresh_token: str
+
+
+class RegisterRequest(BaseModel):
+    username: str
+    email: EmailStr
+    password: str
+    date_of_birth: str  # ISO format date string (YYYY-MM-DD)
+
+    @field_validator("date_of_birth")
+    @classmethod
+    def validate_date_of_birth(cls, v: str) -> str:
+        """Validate that the date string is a valid date in YYYY-MM-DD format."""
+        try:
+            datetime.strptime(v, "%Y-%m-%d")
+        except ValueError:
+            raise ValueError("date_of_birth must be in YYYY-MM-DD format")
+        return v
+
+
+class UserResponse(BaseModel):
+    id: int
+    username: str
+    email: str
+    date_of_birth: str | None = None
+    is_active: bool
+    created_at: datetime | None = None
+
+    model_config = {"from_attributes": True}
+
+
+# --- Helpers ---
+
+def _create_access_token(data: dict) -> str:
+    """Create a signed access token using RS256.
+
+    Includes a unique ``jti`` claim so that concurrent/same-second calls
+    (e.g. back-to-back /refresh requests) still produce distinct tokens —
+    without it, two tokens minted for the same user within the same
+    second are byte-identical since ``sub``/``exp`` are the only claims.
+    """
+    to_encode = data.copy()
+    to_encode["jti"] = str(uuid.uuid4())
+    expire = datetime.now(timezone.utc) + timedelta(
+        minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES
+    )
+    to_encode.update({"exp": expire})
+    return jwt.encode(
+        to_encode,
+        settings.private_pem,
+        algorithm=settings.ALGORITHM,
+    )
+
+
+def _create_refresh_token(data: dict) -> str:
+    """Create a signed refresh token using RS256.
+
+    Includes a unique ``jti`` claim so that concurrent calls produce
+    distinct tokens even when issued within the same second.
+    """
+    to_encode = data.copy()
+    to_encode["jti"] = str(uuid.uuid4())
+    expire = datetime.now(timezone.utc) + timedelta(
+        days=settings.REFRESH_TOKEN_EXPIRE_DAYS
+    )
+    to_encode.update({"exp": expire})
+    return jwt.encode(
+        to_encode,
+        settings.private_pem,
+        algorithm=settings.ALGORITHM,
+    )
+
+
+def verify_password(plain_password: str, hashed_password: str) -> bool:
+    """Verify a plain password against a hash."""
+    return pwd_context.verify(plain_password, hashed_password)
+
+
+def hash_password(password: str) -> str:
+    """Hash a password."""
+    return pwd_context.hash(password)
+
+
+def calculate_age(birth_date: date, today: date | None = None) -> int:
+    """Calculate age in years from a birth date.
+
+    Args:
+        birth_date: The person's date of birth.
+        today: The reference date. Defaults to today's date (UTC).
+
+    Returns:
+        Age in whole years as of the reference date.
+    """
+    if today is None:
+        today = datetime.now(timezone.utc).date()
+
+    age = today.year - birth_date.year
+    # Adjust if birthday hasn't occurred yet this year
+    if (today.month, today.day) < (birth_date.month, birth_date.day):
+        age -= 1
+    return age
+
+
+def _issue_refresh_token(user_id: int, db: AsyncSession) -> str:
+    """Create and persist a refresh token for the given user."""
+    refresh_token_value = _create_refresh_token({"sub": str(user_id)})
+    refresh_token_record = RefreshToken(
+        id=str(uuid.uuid4()),
+        user_id=user_id,
+        token=refresh_token_value,
+        expires_at=datetime.now(timezone.utc)
+        + timedelta(days=settings.REFRESH_TOKEN_EXPIRE_DAYS),
+    )
+    db.add(refresh_token_record)
+    return refresh_token_value
+
+
+# --- Endpoints ---
+
+@router.post("/register", response_model=TokenResponse, status_code=status.HTTP_201_CREATED)
+async def register(req: RegisterRequest, db: AsyncSession = Depends(get_db)):
+    """Register a new user and return access + refresh tokens.
+
+    Requires date_of_birth and rejects users under 18.
+    """
+    # Parse and validate date_of_birth
+    dob = datetime.strptime(req.date_of_birth, "%Y-%m-%d").date()
+    age = calculate_age(dob)
+
+    if age < 18:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail=f"Must be 18 or older to register (provided date of birth: {req.date_of_birth})",
+        )
+
+    # Check if username already exists
+    result = await db.execute(select(User).where(User.username == req.username))
+    if result.scalar_one_or_none():
+        raise HTTPException(
+            status_code=status.HTTP_409_CONFLICT,
+            detail="Username already registered",
+        )
+
+    # Check if email already exists
+    result = await db.execute(select(User).where(User.email == req.email))
+    if result.scalar_one_or_none():
+        raise HTTPException(
+            status_code=status.HTTP_409_CONFLICT,
+            detail="Email already registered",
+        )
+
+    user = User(
+        username=req.username,
+        email=req.email,
+        hashed_password=hash_password(req.password),
+        date_of_birth=dob,
+    )
+    db.add(user)
+    await db.flush()  # flush to get user.id before creating refresh token
+    await db.refresh(user)
+
+    # Create access token
+    access_token = _create_access_token({"sub": str(user.id)})
+
+    # Create and persist refresh token
+    refresh_token_value = _issue_refresh_token(user.id, db)
+    await db.commit()
+
+    return TokenResponse(
+        access_token=access_token,
+        refresh_token=refresh_token_value,
+        access_token_expires_minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES,
+    )
+
+
+@router.post("/login", response_model=TokenResponse)
+async def login(form: OAuth2PasswordRequestForm = Depends(), db: AsyncSession = Depends(get_db)):
+    """Authenticate user and return access + refresh tokens.
+
+    Accepts form-encoded credentials (username/password) as expected by
+    OAuth2PasswordBearer, so the Swagger UI "Authorize" flow works correctly.
+    """
+    result = await db.execute(select(User).where(User.username == form.username))
+    user = result.scalar_one_or_none()
+
+    if not user or not verify_password(form.password, user.hashed_password):
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Incorrect username or password",
+        )
+
+    if not user.is_active:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="User account is inactive",
+        )
+
+    # Create access token
+    access_token = _create_access_token({"sub": str(user.id)})
+
+    # Create and persist refresh token
+    refresh_token_value = _issue_refresh_token(user.id, db)
+    await db.commit()
+
+    return TokenResponse(
+        access_token=access_token,
+        refresh_token=refresh_token_value,
+        access_token_expires_minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES,
+    )
+
+
+@router.post("/refresh", response_model=TokenResponse)
+async def refresh(req: RefreshRequest, db: AsyncSession = Depends(get_db)):
+    """Exchange a valid refresh token for a new access token.
+
+    Validates the refresh token against the database:
+    - Must exist in the refresh_tokens table
+    - Must not be expired (expires_at > now)
+    - Must be active (is_active == true)
+
+    On success, returns a new access token. The refresh token itself is
+    NOT rotated (the client keeps using the same refresh token).
+    """
+    credentials_exception = HTTPException(
+        status_code=status.HTTP_401_UNAUTHORIZED,
+        detail="Invalid or expired refresh token",
+    )
+
+    # Step 1: Decode and validate the JWT signature/claims
+    try:
+        payload = jwt.decode(
+            req.refresh_token,
+            settings.public_pem,
+            algorithms=[settings.ALGORITHM],
+        )
+    except JWTError:
+        raise credentials_exception
+
+    user_id_str: str | None = payload.get("sub")
+    if user_id_str is None:
+        raise credentials_exception
+
+    try:
+        user_id = int(user_id_str)
+    except (ValueError, TypeError):
+        raise credentials_exception
+
+    # Step 2: Look up the refresh token in the database
+    result = await db.execute(
+        select(RefreshToken).where(
+            RefreshToken.token == req.refresh_token,
+            RefreshToken.user_id == user_id,
+        )
+    )
+    stored_token = result.scalar_one_or_none()
+
+    if stored_token is None:
+        raise credentials_exception
+
+    # Step 3: Check if the token is expired
+    if datetime.now(timezone.utc) >= stored_token.expires_at:
+        raise credentials_exception
+
+    # Step 4: Check if the token is active
+    if not stored_token.is_active:
+        raise credentials_exception
+
+    # Step 5: Issue a new access token
+    access_token = _create_access_token({"sub": str(user_id)})
+
+    return TokenResponse(
+        access_token=access_token,
+        refresh_token=req.refresh_token,  # Return the same refresh token
+        access_token_expires_minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES,
+    )
+
+
+@router.get("/me", response_model=UserResponse)
+async def get_current_user(current_user: CurrentUser):
+    """Get current user profile from the JWT token."""
+    return current_user

backend/app/routers/users.py

@@ -0,0 +1,106 @@
+"""User management router."""
+
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from pydantic import BaseModel, EmailStr
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.user import User
+
+router = APIRouter()
+
+
+# ─── Pydantic schemas ────────────────────────────────────────────────────────
+
+class UserResponse(BaseModel):
+    id: int
+    username: str
+    email: str
+    is_active: bool
+
+    model_config = {"from_attributes": True}
+
+
+class UserUpdate(BaseModel):
+    email: EmailStr | None = None
+    is_active: bool | None = None
+
+
+# ─── Endpoints ───────────────────────────────────────────────────────────────
+
+@router.get("/me", response_model=UserResponse)
+async def get_current_user_profile(
+    current_user: CurrentUser,
+):
+    """Get the currently authenticated user's profile."""
+    return current_user
+
+
+@router.get("/{user_id}", response_model=UserResponse)
+async def get_user(
+    user_id: int,
+    current_user: CurrentUser,
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    """Get a user by ID.  Only the owner can view their own profile."""
+    result = await db.execute(select(User).where(User.id == user_id))
+    user = result.scalar_one_or_none()
+    if not user:
+        raise HTTPException(status_code=404, detail="User not found")
+
+    # Only the owner may view their own profile.
+    if user.id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not authorized to view this user")
+
+    return user
+
+
+@router.patch("/{user_id}", response_model=UserResponse)
+async def update_user(
+    user_id: int,
+    user_update: UserUpdate,
+    current_user: CurrentUser,
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    """Update a user.  Only the owner can update their own account."""
+    result = await db.execute(select(User).where(User.id == user_id))
+    user = result.scalar_one_or_none()
+    if not user:
+        raise HTTPException(status_code=404, detail="User not found")
+
+    # Only the owner may update their own account.
+    if user.id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not authorized to update this user")
+
+    if user_update.email is not None:
+        user.email = user_update.email
+    if user_update.is_active is not None:
+        user.is_active = user_update.is_active
+
+    await db.commit()
+    await db.refresh(user)
+    return user
+
+
+@router.delete("/{user_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_user(
+    user_id: int,
+    current_user: CurrentUser,
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    """Delete a user.  Only the owner can delete their own account."""
+    result = await db.execute(select(User).where(User.id == user_id))
+    user = result.scalar_one_or_none()
+    if not user:
+        raise HTTPException(status_code=404, detail="User not found")
+
+    # Only the owner may delete their own account.
+    if user.id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not authorized to delete this user")
+
+    await db.delete(user)
+    await db.commit()

backend/app/routers/worlds.py

@@ -0,0 +1,169 @@
+"""Worlds router - CRUD for game worlds."""
+
+from datetime import datetime
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, HTTPException, Query
+from pydantic import BaseModel, Field
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import selectinload
+
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.world import World, WorldVisibility
+
+router = APIRouter()
+
+DbDep = Annotated[AsyncSession, Depends(get_db)]
+
+
+# --- Pydantic schemas ---
+
+class WorldCreate(BaseModel):
+    """Schema for creating a world."""
+    name: str = Field(..., min_length=1, max_length=255)
+    description: str | None = None
+    visibility: WorldVisibility = WorldVisibility.PUBLIC
+
+
+class WorldUpdate(BaseModel):
+    """Schema for updating a world."""
+    name: str | None = Field(None, min_length=1, max_length=255)
+    description: str | None = None
+    visibility: WorldVisibility | None = None
+
+
+class WorldResponse(BaseModel):
+    """Schema for world responses."""
+    id: int
+    name: str
+    description: str | None
+    visibility: WorldVisibility
+    owner_id: int
+    created_at: datetime | None = None
+
+    model_config = {"from_attributes": True}
+
+
+# --- Endpoints ---
+
+@router.get("/", response_model=list[WorldResponse])
+async def list_worlds(
+    current_user: CurrentUser,
+    db: DbDep,
+    skip: int = Query(0, ge=0),
+    limit: int = Query(50, ge=1, le=100),
+    visibility: WorldVisibility | None = None,
+):
+    """List worlds visible to the current user.
+
+    PUBLIC worlds are visible to everyone.
+    PRIVATE/FRIENDS_ONLY worlds are visible to their owner.
+    """
+    query = select(World).options(selectinload(World.owner))
+
+    # Filter by visibility if specified
+    if visibility:
+        query = query.where(World.visibility == visibility)
+        if visibility != WorldVisibility.PUBLIC:
+            # Requesting a non-public visibility explicitly must not bypass
+            # ownership — otherwise any authenticated user could list every
+            # PRIVATE/FRIENDS_ONLY world in the system just by passing the
+            # filter, defeating the point of the check below.
+            query = query.where(World.owner_id == current_user.id)
+    else:
+        # Show PUBLIC worlds + owner's own worlds
+        query = query.where(
+            (World.visibility == WorldVisibility.PUBLIC)
+            | (World.owner_id == current_user.id)
+        )
+
+    query = query.offset(skip).limit(limit).order_by(World.created_at.desc())
+    result = await db.execute(query)
+    worlds = result.scalars().all()
+    return worlds
+
+
+@router.get("/{world_id}", response_model=WorldResponse)
+async def get_world(
+    world_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Get a single world by ID, respecting visibility."""
+    result = await db.execute(
+        select(World).where(World.id == world_id).options(selectinload(World.owner))
+    )
+    world = result.scalar_one_or_none()
+    if not world:
+        raise HTTPException(status_code=404, detail="World not found")
+
+    # Allow access if world is PUBLIC or owned by current user
+    if world.visibility != WorldVisibility.PUBLIC and world.owner_id != current_user.id:
+        raise HTTPException(status_code=404, detail="World not found")
+
+    return world
+
+
+@router.post("/", response_model=WorldResponse, status_code=201)
+async def create_world(
+    world_data: WorldCreate,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Create a new world."""
+    world = World(
+        name=world_data.name,
+        description=world_data.description,
+        owner_id=current_user.id,
+        visibility=world_data.visibility,
+    )
+    db.add(world)
+    await db.commit()
+    await db.refresh(world)
+    return world
+
+
+@router.put("/{world_id}", response_model=WorldResponse)
+async def update_world(
+    world_id: int,
+    world_data: WorldUpdate,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Update an existing world."""
+    result = await db.execute(select(World).where(World.id == world_id))
+    world = result.scalar_one_or_none()
+    if not world:
+        raise HTTPException(status_code=404, detail="World not found")
+
+    if world.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not owner of this world")
+
+    update_data = world_data.model_dump(exclude_unset=True)
+    for field, value in update_data.items():
+        setattr(world, field, value)
+
+    await db.commit()
+    await db.refresh(world)
+    return world
+
+
+@router.delete("/{world_id}", status_code=204)
+async def delete_world(
+    world_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Delete a world."""
+    result = await db.execute(select(World).where(World.id == world_id))
+    world = result.scalar_one_or_none()
+    if not world:
+        raise HTTPException(status_code=404, detail="World not found")
+
+    if world.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="Not owner of this world")
+
+    await db.delete(world)
+    await db.commit()

backend/app/services/gltf.py

@@ -0,0 +1,197 @@
+"""Lightweight glTF / GLB metadata extraction.
+
+This module intentionally avoids heavyweight dependencies such as trimesh or
+pygltflib. For the metadata fields the asset upload pipeline needs (mesh and
+vertex counts, animation presence, texture references, and the bounding box)
+a small amount of glTF-specific parsing is sufficient and keeps the backend
+dependency-free.
+"""
+
+from __future__ import annotations
+
+import json
+import struct
+from typing import Any, Optional
+
+# GLB binary header magic bytes ("glTF").
+_GLB_MAGIC = b"glTF"
+_GLB_MAGIC_INT = 0x46546C67  # b"glTF" interpreted as little-endian uint32
+_GLB_JSON_CHUNK_TYPE = 0x4E4F534A  # "JSON"
+_GLB_BIN_CHUNK_TYPE = 0x004E4942  # "BIN\0"
+
+# Whitespace allowed around a GLB JSON chunk. The spec pads with spaces (0x20),
+# but be lenient with null bytes and other whitespace that real exporters emit.
+_JSON_CHUNK_TRIM = b" \t\r\n\x00"
+
+
+def looks_like_gltf(content: bytes, filename: Optional[str] = None) -> bool:
+    """Return True when the bytes or filename indicate a glTF/GLB asset."""
+    if content.startswith(_GLB_MAGIC):
+        return True
+
+    if filename:
+        lowered = filename.lower()
+        if lowered.endswith(".gltf") or lowered.endswith(".glb"):
+            return True
+
+    # A bare JSON buffer (e.g. uploaded without an extension) that has the
+    # glTF asset marker is also a glTF file.
+    stripped = content.lstrip()
+    if stripped.startswith(b"{"):
+        try:
+            payload = json.loads(stripped.decode("utf-8"))
+        except (ValueError, UnicodeDecodeError):
+            return False
+        return isinstance(payload, dict) and "asset" in payload and "version" in payload.get("asset", {})
+
+    return False
+
+
+def _parse_glb(content: bytes) -> dict[str, Any]:
+    """Parse the JSON chunk of a GLB binary container."""
+    if len(content) < 12:
+        raise ValueError("GLB file is too short")
+
+    magic, _version, _length = struct.unpack_from("<III", content, 0)
+    if magic != _GLB_MAGIC_INT:
+        raise ValueError("invalid GLB magic")
+
+    offset = 12
+    json_chunk: Optional[dict[str, Any]] = None
+
+    while offset + 8 <= len(content):
+        chunk_length, chunk_type = struct.unpack_from("<II", content, offset)
+        offset += 8
+        chunk_end = offset + chunk_length
+        if chunk_end > len(content):
+            raise ValueError("GLB chunk overruns file boundary")
+
+        chunk_data = content[offset:chunk_end]
+        if chunk_type == _GLB_JSON_CHUNK_TYPE:
+            try:
+                json_chunk = json.loads(chunk_data.strip(_JSON_CHUNK_TRIM).decode("utf-8"))
+            except (ValueError, UnicodeDecodeError) as exc:
+                raise ValueError(f"invalid GLB JSON chunk: {exc}") from exc
+
+        offset = chunk_end
+
+    if json_chunk is None:
+        raise ValueError("GLB file does not contain a JSON chunk")
+
+    return json_chunk
+
+
+def _parse_gltf_json(content: bytes) -> dict[str, Any]:
+    """Parse a plain .gltf JSON file."""
+    stripped = content.lstrip()
+    try:
+        payload = json.loads(stripped.decode("utf-8"))
+    except (ValueError, UnicodeDecodeError) as exc:
+        raise ValueError(f"invalid glTF JSON: {exc}") from exc
+
+    if not isinstance(payload, dict):
+        raise ValueError("glTF JSON root must be an object")
+    return payload
+
+
+def _position_accessor_counts(gltf: dict[str, Any]) -> list[int]:
+    """Return POSITION accessor counts for every mesh primitive."""
+    counts: list[int] = []
+    accessors = gltf.get("accessors", [])
+    for mesh in gltf.get("meshes", []):
+        for primitive in mesh.get("primitives", []):
+            attributes = primitive.get("attributes", {})
+            position_index = attributes.get("POSITION")
+            if position_index is None:
+                continue
+            try:
+                accessor = accessors[int(position_index)]
+            except (IndexError, TypeError, ValueError):
+                continue
+            count = accessor.get("count")
+            if isinstance(count, int):
+                counts.append(count)
+    return counts
+
+
+def _position_bounds(gltf: dict[str, Any]) -> list[list[float]]:
+    """Return min/max bounds for every POSITION accessor that declares them."""
+    bounds: list[list[float]] = []
+    accessors = gltf.get("accessors", [])
+    for mesh in gltf.get("meshes", []):
+        for primitive in mesh.get("primitives", []):
+            attributes = primitive.get("attributes", {})
+            position_index = attributes.get("POSITION")
+            if position_index is None:
+                continue
+            try:
+                accessor = accessors[int(position_index)]
+            except (IndexError, TypeError, ValueError):
+                continue
+            minimum = accessor.get("min")
+            maximum = accessor.get("max")
+            if isinstance(minimum, list) and isinstance(maximum, list):
+                bounds.append([float(x) for x in minimum])
+                bounds.append([float(x) for x in maximum])
+    return bounds
+
+
+def _texture_refs(gltf: dict[str, Any]) -> list[str]:
+    """Collect external texture source references from the image array."""
+    refs: list[str] = []
+    for index, image in enumerate(gltf.get("images", [])):
+        uri = image.get("uri")
+        if isinstance(uri, str) and not uri.startswith("data:"):
+            refs.append(uri)
+            continue
+
+        name = image.get("name")
+        if isinstance(name, str) and name:
+            refs.append(name)
+            continue
+
+        if isinstance(uri, str):
+            # Embedded data URI; keep a stable, non-huge reference.
+            refs.append(f"data:{index}")
+            continue
+
+        buffer_view = image.get("bufferView")
+        if buffer_view is not None:
+            refs.append(f"bufferView:{buffer_view}")
+            continue
+
+        refs.append(f"image:{index}")
+
+    return refs
+
+
+def extract_gltf_metadata(content: bytes) -> dict[str, Any]:
+    """Extract upload-relevant metadata from glTF/GLB bytes.
+
+    Raises ValueError for malformed glTF content. The returned dict contains:
+        mesh_count, vertex_count, has_animation, texture_refs,
+        bounding_box_min, bounding_box_max.
+    """
+    if content.startswith(_GLB_MAGIC):
+        gltf = _parse_glb(content)
+    else:
+        gltf = _parse_gltf_json(content)
+
+    position_counts = _position_accessor_counts(gltf)
+    bounds = _position_bounds(gltf)
+
+    if bounds:
+        bounding_box_min = [min(axis) for axis in zip(*bounds[::2])]
+        bounding_box_max = [max(axis) for axis in zip(*bounds[1::2])]
+    else:
+        bounding_box_min = [0.0, 0.0, 0.0]
+        bounding_box_max = [0.0, 0.0, 0.0]
+
+    return {
+        "mesh_count": len(gltf.get("meshes", [])),
+        "vertex_count": sum(position_counts),
+        "has_animation": bool(gltf.get("animations")),
+        "texture_refs": _texture_refs(gltf),
+        "bounding_box_min": bounding_box_min,
+        "bounding_box_max": bounding_box_max,
+    }

backend/docker-compose.yml

@@ -0,0 +1,34 @@
+version: "3.9"
+
+services:
+  postgres:
+    image: postgres:16-alpine
+    environment:
+      POSTGRES_USER: agp_user
+      POSTGRES_PASSWORD: agp_password
+      POSTGRES_DB: agp_db
+    ports:
+      - "${POSTGRES_HOST_PORT:-5432}:5432"
+    volumes:
+      - postgres_data:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U agp_user -d agp_db"]
+      interval: 5s
+      timeout: 5s
+      retries: 5
+
+  redis:
+    image: redis:7-alpine
+    ports:
+      - "${REDIS_HOST_PORT:-6379}:6379"
+    volumes:
+      - redis_data:/data
+    healthcheck:
+      test: ["CMD", "redis-cli", "ping"]
+      interval: 5s
+      timeout: 5s
+      retries: 5
+
+volumes:
+  postgres_data:
+  redis_data:

backend/pytest.ini

@@ -0,0 +1,3 @@
+[pytest]
+asyncio_mode = auto
+testpaths = tests

backend/requirements.txt

@@ -0,0 +1,25 @@
+fastapi==0.115.6
+uvicorn[standard]==0.34.0
+sqlalchemy==2.0.36
+alembic==1.14.0
+psycopg2-binary==2.9.10
+asyncpg==0.31.0
+redis==5.2.1
+pydantic==2.10.3
+pydantic-settings==2.7.0
+python-jose[cryptography]==3.3.0
+passlib[bcrypt]==1.7.4
+# passlib 1.7.4 (last release, unmaintained since ~2020) detects its bcrypt
+# backend via bcrypt.__about__.__version__, which bcrypt>=4.1 removed --
+# hashing/verifying a password then raises "password cannot be longer than
+# 72 bytes" (a misleading downstream symptom of the real AttributeError:
+# module 'bcrypt' has no attribute '__about__') on every call. Without this
+# pin, `pip install -r requirements.txt` silently grabs whatever the latest
+# bcrypt is and breaks register/login outright. Pin below 4.1 explicitly.
+bcrypt==4.0.1
+python-multipart==0.0.20
+email-validator==2.2.0
+httpx==0.28.1
+pytest==8.3.4
+pytest-asyncio==0.25.0
+pytest-cov==6.0.0

backend/tests/conftest.py

@@ -0,0 +1,38 @@
+"""Shared pytest fixtures.
+
+The auth integration tests hit the *real* Postgres database (per
+``DATABASE_URL``), so they persist data between runs.  Without cleanup a
+second run of the suite fails with 409 conflicts because the users it
+registered on the first run already exist.  The session-scoped fixture below
+truncates all application tables once before the first test, making the suite
+re-runnable.
+
+Truncation order doesn't strictly matter because ``CASCADE`` follows foreign
+keys, but the tables are listed explicitly for clarity.
+"""
+
+import asyncio
+
+import pytest
+from sqlalchemy import text
+from sqlalchemy.ext.asyncio import create_async_engine
+
+from app.config import settings
+
+TEST_TABLES = ("assets", "worlds", "sessions", "refresh_tokens", "users")
+
+
+@pytest.fixture(scope="session", autouse=True)
+def _reset_database():
+    """Truncate all application tables once per test session."""
+
+    async def _truncate() -> None:
+        engine = create_async_engine(settings.DATABASE_URL)
+        async with engine.begin() as conn:
+            await conn.execute(
+                text(f"TRUNCATE TABLE {', '.join(TEST_TABLES)} CASCADE")
+            )
+        await engine.dispose()
+
+    asyncio.run(_truncate())
+    yield

backend/tests/test_auth_age_gate.py

@@ -0,0 +1,94 @@
+"""Tests for the 18+ age gate on user registration."""
+
+from datetime import date, timedelta
+
+import pytest
+
+from app.routers.auth import calculate_age
+
+
+class TestCalculateAge:
+    """Unit tests for the calculate_age helper."""
+
+    def test_exactly_18(self):
+        """A person born exactly 18 years ago today is 18."""
+        today = date(2025, 6, 15)
+        dob = today.replace(year=today.year - 18)
+        assert calculate_age(dob, today=today) == 18
+
+    def test_just_turned_18(self):
+        """A person who turned 18 yesterday is 18."""
+        today = date(2025, 6, 15)
+        dob = today.replace(year=today.year - 18) - timedelta(days=1)
+        assert calculate_age(dob, today=today) == 18
+
+    def test_one_day_short_of_18(self):
+        """A person born one day after their 18th birthday is 17."""
+        today = date(2025, 6, 15)
+        dob = today.replace(year=today.year - 18) + timedelta(days=1)
+        assert calculate_age(dob, today=today) == 17
+
+    def test_17_years_old(self):
+        """A person who is 17 years old today is 17."""
+        today = date(2025, 6, 15)
+        dob = date(2008, 6, 15)
+        assert calculate_age(dob, today=today) == 17
+
+    def test_65_years_old(self):
+        """A person who is 65 is correctly calculated."""
+        today = date(2025, 6, 15)
+        dob = today.replace(year=today.year - 65)
+        assert calculate_age(dob, today=today) == 65
+
+    def test_newborn(self):
+        """A newborn is 0."""
+        today = date(2025, 6, 15)
+        dob = today
+        assert calculate_age(dob, today=today) == 0
+
+    def test_birthday_not_yet_this_year(self):
+        """Person born Dec 31, 2000 — on Jan 1, 2025 they are still 24."""
+        dob = date(2000, 12, 31)
+        assert calculate_age(dob, today=date(2025, 1, 1)) == 24
+
+    def test_birthday_today(self):
+        """Person born Dec 31, 2000 — on Dec 31, 2024 they turn 24."""
+        dob = date(2000, 12, 31)
+        assert calculate_age(dob, today=date(2024, 12, 31)) == 24
+
+
+class TestRegisterRequestDateValidation:
+    """Tests for the RegisterRequest date_of_birth field validator."""
+
+    @pytest.mark.parametrize(
+        "dob",
+        [
+            "2000-01-01",
+            "1990-12-31",
+            "2004-02-29",  # leap day
+        ],
+    )
+    def test_valid_dates(self, dob):
+        """Valid YYYY-MM-DD dates pass validation."""
+        from app.routers.auth import RegisterRequest
+
+        req = RegisterRequest(username="u", email="u@example.com", password="p", date_of_birth=dob)
+        assert req.date_of_birth == dob
+
+    @pytest.mark.parametrize(
+        "dob",
+        [
+            "01-01-2000",
+            "2000/01/01",
+            "2000-13-01",
+            "2000-00-10",
+            "not-a-date",
+            "",
+        ],
+    )
+    def test_invalid_dates_rejected(self, dob):
+        """Invalid dates are rejected by the validator."""
+        from app.routers.auth import RegisterRequest
+
+        with pytest.raises(ValueError):
+            RegisterRequest(username="u", email="u@example.com", password="p", date_of_birth=dob)

backend/tests/test_auth_endpoints.py

@@ -0,0 +1,263 @@
+"""Integration tests for the auth endpoints (register + login).
+
+These tests hit the real FastAPI app against the real configured database
+(DATABASE_URL -- Postgres via Alembic migrations in CI/dev, not an isolated
+in-memory DB), so they exercise the full stack: Pydantic validation → DB →
+JWT → response. Requires migrations already applied (alembic upgrade head)
+before running.
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from sqlalchemy.pool import NullPool
+
+from app.config import settings
+from app.main import app
+from app.database import get_db
+from app.routers.auth import pwd_context
+
+
+# ---------------------------------------------------------------------------
+# Test fixtures
+# ---------------------------------------------------------------------------
+
+@pytest.fixture(autouse=True)
+def _override_db():
+    """Override get_db so the app uses a fresh session per test.
+
+    Deliberately does NOT reuse app.database's shared engine: FastAPI's
+    (sync) TestClient runs each request through anyio's blocking-portal
+    machinery, which can hand different requests different event loops.
+    asyncpg connections are bound to the loop they were created on, so
+    reusing one from the shared engine's connection pool across requests
+    raises "cannot perform operation: another operation is in progress" the
+    moment a test makes more than one request (register-then-login,
+    register-twice, etc.) -- confirmed this is the actual cause, not a bug
+    in the endpoints themselves. NullPool sidesteps it: every checkout is a
+    brand-new connection, never handed to a different loop than the one
+    that opened it.
+    """
+    test_engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+    test_session_factory = async_sessionmaker(test_engine, expire_on_commit=False)
+
+    async def _get_db():
+        async_session = test_session_factory()
+        try:
+            yield async_session
+            await async_session.commit()
+        except Exception:
+            await async_session.rollback()
+            raise
+        finally:
+            await async_session.close()
+
+    app.dependency_overrides[get_db] = _get_db
+    yield
+    app.dependency_overrides.clear()
+
+
+# ---------------------------------------------------------------------------
+# Register endpoint
+# ---------------------------------------------------------------------------
+
+class TestRegister:
+    """Tests for POST /api/auth/register."""
+
+    def test_register_success(self):
+        """A valid registration returns 201 with a token."""
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/register",
+            json={
+                "username": "newuser",
+                "email": "new@example.com",
+                "password": "secret123",
+                "date_of_birth": "2000-01-01",
+            },
+        )
+        assert resp.status_code == 201
+        data = resp.json()
+        assert "access_token" in data
+        assert data["token_type"] == "bearer"
+
+    def test_register_rejects_underage(self):
+        """Users under 18 get a 400 with a detail message."""
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/register",
+            json={
+                "username": "kid",
+                "email": "kid@example.com",
+                "password": "secret123",
+                "date_of_birth": "2010-06-15",  # ~15 years old
+            },
+        )
+        assert resp.status_code == 400
+        assert "18 or older" in resp.json()["detail"]
+
+    def test_register_rejects_duplicate_username(self):
+        """Registering the same username twice returns 409."""
+        client = TestClient(app)
+        # First registration
+        client.post(
+            "/api/auth/register",
+            json={
+                "username": "duplicate",
+                "email": "dup1@example.com",
+                "password": "secret123",
+                "date_of_birth": "2000-01-01",
+            },
+        )
+        # Second registration with same username, different email
+        resp = client.post(
+            "/api/auth/register",
+            json={
+                "username": "duplicate",
+                "email": "dup2@example.com",
+                "password": "secret123",
+                "date_of_birth": "2000-01-01",
+            },
+        )
+        assert resp.status_code == 409
+        assert "Username already registered" in resp.json()["detail"]
+
+    def test_register_rejects_duplicate_email(self):
+        """Registering the same email twice returns 409."""
+        client = TestClient(app)
+        client.post(
+            "/api/auth/register",
+            json={
+                "username": "user1",
+                "email": "same@example.com",
+                "password": "secret123",
+                "date_of_birth": "2000-01-01",
+            },
+        )
+        resp = client.post(
+            "/api/auth/register",
+            json={
+                "username": "user2",
+                "email": "same@example.com",
+                "password": "secret123",
+                "date_of_birth": "2000-01-01",
+            },
+        )
+        assert resp.status_code == 409
+        assert "Email already registered" in resp.json()["detail"]
+
+    def test_register_invalid_date_format(self):
+        """Invalid date format returns 422 validation error."""
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/register",
+            json={
+                "username": "user",
+                "email": "user@example.com",
+                "password": "secret123",
+                "date_of_birth": "01-01-2000",  # wrong format
+            },
+        )
+        assert resp.status_code == 422
+
+    def test_register_exactly_18(self):
+        """A user who just turned 18 can register."""
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/register",
+            json={
+                "username": "just18",
+                "email": "just18@example.com",
+                "password": "secret123",
+                "date_of_birth": "2007-06-15",
+            },
+        )
+        assert resp.status_code == 201
+
+
+# ---------------------------------------------------------------------------
+# Login endpoint
+# ---------------------------------------------------------------------------
+
+class TestLogin:
+    """Tests for POST /api/auth/login."""
+
+    def _create_user(self, username: str, password: str, email: str = None):
+        """Helper to create a user via register."""
+        client = TestClient(app)
+        if email is None:
+            email = f"{username}@example.com"
+        resp = client.post(
+            "/api/auth/register",
+            json={
+                "username": username,
+                "email": email,
+                "password": password,
+                "date_of_birth": "2000-01-01",
+            },
+        )
+        assert resp.status_code == 201
+        return resp.json()["access_token"]
+
+    def test_login_success(self):
+        """Correct credentials return a token."""
+        self._create_user("loginuser", "correctpass")
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/login",
+            data={"username": "loginuser", "password": "correctpass"},
+        )
+        assert resp.status_code == 200
+        data = resp.json()
+        assert "access_token" in data
+        assert data["token_type"] == "bearer"
+
+    def test_login_wrong_password(self):
+        """Wrong password returns 401."""
+        # Distinct username from test_login_success -- there's no per-test
+        # DB rollback/isolation here (real Postgres via the app's own
+        # dependency-overridden session), so reusing "loginuser" collided
+        # with the user that test already created (409 on register instead
+        # of the intended 401-on-login assertion this test is actually for).
+        self._create_user("loginuser_wrongpass", "correctpass")
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/login",
+            data={"username": "loginuser_wrongpass", "password": "wrongpass"},
+        )
+        assert resp.status_code == 401
+        assert "Incorrect username or password" in resp.json()["detail"]
+
+    def test_login_nonexistent_user(self):
+        """Non-existent user returns 401 (not 404)."""
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/login",
+            data={"username": "nobody", "password": "any"},
+        )
+        assert resp.status_code == 401
+        assert "Incorrect username or password" in resp.json()["detail"]
+
+    def test_login_accepts_form_encoded(self):
+        """Login accepts application/x-www-form-urlencoded (OAuth2)."""
+        self._create_user("formuser", "formpass")
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/login",
+            data={"username": "formuser", "password": "formpass"},
+        )
+        assert resp.status_code == 200
+        assert "access_token" in resp.json()
+
+    def test_login_token_is_valid_jwt(self):
+        """The returned token is a valid JWT that can be decoded."""
+        self._create_user("jwttoken", "jwt123")
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/login",
+            data={"username": "jwttoken", "password": "jwt123"},
+        )
+        token = resp.json()["access_token"]
+        # Verify it's a 3-part JWT
+        parts = token.split(".")
+        assert len(parts) == 3

backend/tests/test_auth_expired_token.py

@@ -0,0 +1,171 @@
+"""Tests for expired-token rejection across auth endpoints.
+
+Covers two distinct expiry paths:
+
+1. An *access* JWT whose ``exp`` claim is in the past must be rejected
+   with 401 by ``GET /api/auth/me`` (jose's built-in ``exp`` validation).
+2. A *refresh* token whose persisted ``expires_at`` is in the past must be
+   rejected with 401 by ``POST /api/auth/refresh`` even though its JWT
+   signature is still valid.
+
+Requires migrations already applied (alembic upgrade head) before running.
+"""
+
+import asyncio
+from datetime import datetime, timedelta, timezone
+
+import pytest
+from fastapi.testclient import TestClient
+from jose import jwt
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from sqlalchemy.pool import NullPool
+
+from app.config import settings
+from app.main import app
+from app.database import get_db
+from app.models.session import RefreshToken
+
+
+# ---------------------------------------------------------------------------
+# Test fixtures
+# ---------------------------------------------------------------------------
+
+@pytest.fixture(autouse=True)
+def _override_db():
+    """Override get_db so the app uses a fresh session per test."""
+    test_engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+    test_session_factory = async_sessionmaker(test_engine, expire_on_commit=False)
+
+    async def _get_db():
+        async_session = test_session_factory()
+        try:
+            yield async_session
+            await async_session.commit()
+        except Exception:
+            await async_session.rollback()
+            raise
+        finally:
+            await async_session.close()
+
+    app.dependency_overrides[get_db] = _get_db
+    yield
+    app.dependency_overrides.clear()
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+def _mint_access_token(exp: datetime) -> str:
+    """Mint an RS256 access token with an explicit ``exp`` claim."""
+    return jwt.encode(
+        {"sub": "1", "exp": exp},
+        settings.private_pem,
+        algorithm=settings.ALGORITHM,
+    )
+
+
+def _expire_refresh_token_in_db(token: str) -> None:
+    """Set the persisted refresh token's ``expires_at`` into the past."""
+
+    async def _do():
+        engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+        session_factory = async_sessionmaker(engine, expire_on_commit=False)
+        async with session_factory() as session:
+            from sqlalchemy import update
+
+            await session.execute(
+                update(RefreshToken)
+                .where(RefreshToken.token == token)
+                .values(expires_at=datetime.now(timezone.utc) - timedelta(hours=1))
+            )
+            await session.commit()
+        await engine.dispose()
+
+    asyncio.run(_do())
+
+
+def _register_user(client: TestClient, username: str) -> str:
+    """Register a user and return its refresh token."""
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "2000-01-01",
+        },
+    )
+    assert resp.status_code == 201
+    return resp.json()["refresh_token"]
+
+
+# ---------------------------------------------------------------------------
+# Expired access token (GET /api/auth/me)
+# ---------------------------------------------------------------------------
+
+class TestExpiredAccessToken:
+    def test_expired_access_token_is_rejected_by_me(self):
+        """An access JWT with a past exp claim returns 401 on /me."""
+        client = TestClient(app)
+        expired_token = _mint_access_token(
+            datetime.now(timezone.utc) - timedelta(minutes=5)
+        )
+        resp = client.get(
+            "/api/auth/me",
+            headers={"Authorization": f"Bearer {expired_token}"},
+        )
+        assert resp.status_code == 401
+        assert "Could not validate credentials" in resp.json()["detail"]
+
+    def test_garbage_access_token_is_rejected_by_me(self):
+        """A non-JWT bearer token returns 401 on /me."""
+        client = TestClient(app)
+        resp = client.get(
+            "/api/auth/me",
+            headers={"Authorization": "Bearer not-a-real-jwt"},
+        )
+        assert resp.status_code == 401
+
+    def test_missing_bearer_token_returns_401(self):
+        """No Authorization header at all returns 401 on /me."""
+        client = TestClient(app)
+        resp = client.get("/api/auth/me")
+        assert resp.status_code == 401
+
+
+# ---------------------------------------------------------------------------
+# Expired refresh token (POST /api/auth/refresh)
+# ---------------------------------------------------------------------------
+
+class TestExpiredRefreshToken:
+    def test_expired_refresh_token_is_rejected(self):
+        """A refresh token whose DB expires_at is in the past returns 401."""
+        client = TestClient(app)
+        refresh_token = _register_user(client, "expired_rt_user")
+
+        # Force the persisted record to be expired while its JWT signature
+        # is still valid.
+        _expire_refresh_token_in_db(refresh_token)
+
+        resp = client.post(
+            "/api/auth/refresh",
+            json={"refresh_token": refresh_token},
+        )
+        assert resp.status_code == 401
+        assert "Invalid or expired refresh token" in resp.json()["detail"]
+
+    def test_expired_refresh_token_jwt_is_rejected(self):
+        """A refresh JWT with a past exp claim is rejected before DB lookup."""
+        client = TestClient(app)
+        expired_jwt = jwt.encode(
+            {"sub": "1", "exp": datetime.now(timezone.utc) - timedelta(minutes=5)},
+            settings.private_pem,
+            algorithm=settings.ALGORITHM,
+        )
+        resp = client.post(
+            "/api/auth/refresh",
+            json={"refresh_token": expired_jwt},
+        )
+        assert resp.status_code == 401
+        assert "Invalid or expired refresh token" in resp.json()["detail"]

backend/tests/test_gltf_metadata.py

@@ -0,0 +1,220 @@
+"""Tests for the lightweight glTF metadata extraction service."""
+
+import json
+import struct
+import pytest
+
+from app.services.gltf import (
+    extract_gltf_metadata,
+    looks_like_gltf,
+    _parse_glb,
+    _parse_gltf_json,
+)
+
+
+# ---------------------------------------------------------------------------
+# Test data helpers
+# ---------------------------------------------------------------------------
+
+def _make_gltf_json(
+    meshes: int = 1,
+    vertices_per_mesh: int = 24,
+    has_animations: bool = False,
+    images: list[dict] | None = None,
+) -> dict:
+    """Build a minimal glTF JSON structure."""
+    accessors = []
+    meshes_data = []
+    for i in range(meshes):
+        acc_index = len(accessors)
+        accessors.append({
+            "bufferView": 0,
+            "componentType": 5126,  # FLOAT
+            "count": vertices_per_mesh,
+            "type": "VEC3",
+            "max": [1.0, 1.0, 1.0],
+            "min": [-1.0, -1.0, -1.0],
+        })
+        meshes_data.append({
+            "primitives": [{
+                "attributes": {"POSITION": acc_index},
+            }],
+        })
+    gltf = {
+        "asset": {"version": "2.0"},
+        "accessors": accessors,
+        "meshes": meshes_data,
+    }
+    if has_animations:
+        gltf["animations"] = [{"name": "anim1", "channels": [], "samplers": []}]
+    if images:
+        gltf["images"] = images
+    return gltf
+
+
+def _make_glb(gltf_json: dict) -> bytes:
+    """Wrap *gltf_json* in a minimal GLB binary container."""
+    json_bytes = json.dumps(gltf_json).encode("utf-8")
+    json_length = len(json_bytes)
+    # Pad JSON chunk to 4-byte boundary.
+    json_padding = (4 - json_length % 4) % 4
+    json_chunk = json_bytes + b"\x00" * json_padding
+    json_chunk_type = 0x4E4F534A  # "JSON"
+    # No BIN chunk.
+    bin_length = 0
+    bin_chunk_type = 0x004E4942
+    total_length = 12 + 8 + len(json_chunk) + 8 + bin_length
+    header = struct.pack("<III", 0x46546C67, 2, total_length)  # magic, version, length
+    json_header = struct.pack("<II", len(json_chunk), json_chunk_type)
+    if bin_length > 0:
+        bin_header = struct.pack("<II", bin_length, bin_chunk_type)
+    else:
+        bin_header = b""
+    return header + json_header + json_chunk + bin_header
+
+
+# ---------------------------------------------------------------------------
+# looks_like_gltf
+# ---------------------------------------------------------------------------
+
+class TestLooksLikeGltf:
+    def test_glb_magic(self):
+        assert looks_like_gltf(b"glTF\x00\x00\x00\x00") is True
+
+    def test_gltf_extension(self):
+        assert looks_like_gltf(b'{"asset":{"version":"2.0"}}', "model.gltf") is True
+
+    def test_glb_extension(self):
+        assert looks_like_gltf(b"some binary", "model.glb") is True
+
+    def test_json_with_asset_version(self):
+        payload = json.dumps({"asset": {"version": "2.0"}}).encode()
+        assert looks_like_gltf(payload) is True
+
+    def test_plain_json_no_asset(self):
+        payload = json.dumps({"foo": "bar"}).encode()
+        assert looks_like_gltf(payload) is False
+
+    def test_non_json_bytes(self):
+        assert looks_like_gltf(b"\x89PNG\r\n\x1a\n") is False
+
+
+# ---------------------------------------------------------------------------
+# _parse_glb
+# ---------------------------------------------------------------------------
+
+class TestParseGlb:
+    def test_parses_valid_glb(self):
+        gltf_json = _make_gltf_json()
+        glb = _make_glb(gltf_json)
+        result = _parse_glb(glb)
+        assert result["asset"]["version"] == "2.0"
+        assert len(result["meshes"]) == 1
+
+    def test_rejects_too_short(self):
+        with pytest.raises(ValueError, match="too short"):
+            _parse_glb(b"glTF\x00\x00")
+
+    def test_rejects_invalid_magic(self):
+        with pytest.raises(ValueError, match="invalid GLB magic"):
+            _parse_glb(b"NOTglTF\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00")
+
+
+# ---------------------------------------------------------------------------
+# _parse_gltf_json
+# ---------------------------------------------------------------------------
+
+class TestParseGltfJson:
+    def test_parses_valid_gltf(self):
+        gltf_json = _make_gltf_json()
+        result = _parse_gltf_json(json.dumps(gltf_json).encode())
+        assert result["asset"]["version"] == "2.0"
+
+    def test_rejects_non_object(self):
+        with pytest.raises(ValueError, match="root must be an object"):
+            _parse_gltf_json(b"[1, 2, 3]")
+
+
+# ---------------------------------------------------------------------------
+# extract_gltf_metadata  (GLB path)
+# ---------------------------------------------------------------------------
+
+class TestExtractGltfMetadataGlb:
+    def test_basic_glb(self):
+        gltf_json = _make_gltf_json(meshes=1, vertices_per_mesh=24)
+        glb = _make_glb(gltf_json)
+        meta = extract_gltf_metadata(glb)
+        assert meta["mesh_count"] == 1
+        assert meta["vertex_count"] == 24
+        assert meta["has_animation"] is False
+        assert meta["bounding_box_min"] == [-1.0, -1.0, -1.0]
+        assert meta["bounding_box_max"] == [1.0, 1.0, 1.0]
+        assert meta["texture_refs"] == []
+
+    def test_multiple_meshes(self):
+        gltf_json = _make_gltf_json(meshes=3, vertices_per_mesh=12)
+        glb = _make_glb(gltf_json)
+        meta = extract_gltf_metadata(glb)
+        assert meta["mesh_count"] == 3
+        assert meta["vertex_count"] == 36
+
+    def test_with_animation(self):
+        gltf_json = _make_gltf_json(has_animations=True)
+        glb = _make_glb(gltf_json)
+        meta = extract_gltf_metadata(glb)
+        assert meta["has_animation"] is True
+
+    def test_with_external_texture(self):
+        gltf_json = _make_gltf_json(images=[{"uri": "textures/rock.png"}])
+        glb = _make_glb(gltf_json)
+        meta = extract_gltf_metadata(glb)
+        assert meta["texture_refs"] == ["textures/rock.png"]
+
+    def test_with_named_texture(self):
+        gltf_json = _make_gltf_json(images=[{"name": "my_texture"}])
+        glb = _make_glb(gltf_json)
+        meta = extract_gltf_metadata(glb)
+        assert meta["texture_refs"] == ["my_texture"]
+
+    def test_empty_meshes(self):
+        gltf_json = _make_gltf_json(meshes=0)
+        glb = _make_glb(gltf_json)
+        meta = extract_gltf_metadata(glb)
+        assert meta["mesh_count"] == 0
+        assert meta["vertex_count"] == 0
+        assert meta["bounding_box_min"] == [0.0, 0.0, 0.0]
+        assert meta["bounding_box_max"] == [0.0, 0.0, 0.0]
+
+
+# ---------------------------------------------------------------------------
+# extract_gltf_metadata  (plain .gltf JSON path)
+# ---------------------------------------------------------------------------
+
+class TestExtractGltfMetadataGltfJson:
+    def test_plain_gltf(self):
+        gltf_json = _make_gltf_json(meshes=2, vertices_per_mesh=8)
+        raw = json.dumps(gltf_json).encode()
+        meta = extract_gltf_metadata(raw)
+        assert meta["mesh_count"] == 2
+        assert meta["vertex_count"] == 16
+        assert meta["has_animation"] is False
+
+    def test_plain_gltf_with_animation(self):
+        gltf_json = _make_gltf_json(has_animations=True)
+        raw = json.dumps(gltf_json).encode()
+        meta = extract_gltf_metadata(raw)
+        assert meta["has_animation"] is True
+
+
+# ---------------------------------------------------------------------------
+# Error handling
+# ---------------------------------------------------------------------------
+
+class TestExtractGltfMetadataErrors:
+    def test_invalid_glb(self):
+        with pytest.raises(ValueError):
+            extract_gltf_metadata(b"not a glb")
+
+    def test_invalid_gltf_json(self):
+        with pytest.raises(ValueError):
+            _parse_gltf_json(b"[1, 2, 3]")

backend/tests/test_refresh_endpoint.py

@@ -0,0 +1,201 @@
+"""Tests for the POST /api/auth/refresh endpoint.
+
+These tests exercise the full stack: register → get refresh token →
+refresh → new access token.  Requires migrations already applied
+(alembic upgrade head) before running.
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from sqlalchemy.pool import NullPool
+
+from app.config import settings
+from app.main import app
+from app.database import get_db
+
+
+# ---------------------------------------------------------------------------
+# Test fixtures
+# ---------------------------------------------------------------------------
+
+@pytest.fixture(autouse=True)
+def _override_db():
+    """Override get_db so the app uses a fresh session per test."""
+    test_engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+    test_session_factory = async_sessionmaker(test_engine, expire_on_commit=False)
+
+    async def _get_db():
+        async_session = test_session_factory()
+        try:
+            yield async_session
+            await async_session.commit()
+        except Exception:
+            await async_session.rollback()
+            raise
+        finally:
+            await async_session.close()
+
+    app.dependency_overrides[get_db] = _get_db
+    yield
+    app.dependency_overrides.clear()
+
+
+# ---------------------------------------------------------------------------
+# Refresh endpoint tests
+# ---------------------------------------------------------------------------
+
+class TestRefresh:
+    """Tests for POST /api/auth/refresh."""
+
+    def _register_user(self, username: str, password: str, email: str = None):
+        """Helper to register a user and return the refresh token."""
+        client = TestClient(app)
+        if email is None:
+            email = f"{username}@example.com"
+        resp = client.post(
+            "/api/auth/register",
+            json={
+                "username": username,
+                "email": email,
+                "password": password,
+                "date_of_birth": "2000-01-01",
+            },
+        )
+        assert resp.status_code == 201
+        return resp.json()["refresh_token"]
+
+    def test_refresh_success(self):
+        """A valid refresh token returns a new access token."""
+        refresh_token = self._register_user("refep_refreshuser", "secret123")
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/refresh",
+            json={"refresh_token": refresh_token},
+        )
+        assert resp.status_code == 200
+        data = resp.json()
+        assert "access_token" in data
+        assert data["token_type"] == "bearer"
+        # The refresh token in the response is the same one we sent
+        assert data["refresh_token"] == refresh_token
+
+    def test_refresh_returns_different_access_token(self):
+        """Refreshing produces a new access token (different from any previous)."""
+        refresh_token = self._register_user("refep_refreshtoken", "secret123")
+        client = TestClient(app)
+
+        # First refresh
+        resp1 = client.post(
+            "/api/auth/refresh",
+            json={"refresh_token": refresh_token},
+        )
+        assert resp1.status_code == 200
+        access_token_1 = resp1.json()["access_token"]
+
+        # Second refresh
+        resp2 = client.post(
+            "/api/auth/refresh",
+            json={"refresh_token": refresh_token},
+        )
+        assert resp2.status_code == 200
+        access_token_2 = resp2.json()["access_token"]
+
+        # Each refresh should produce a new access token
+        assert access_token_1 != access_token_2
+
+    def test_refresh_invalid_token(self):
+        """An invalid (garbage) refresh token returns 401."""
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/refresh",
+            json={"refresh_token": "not.a.jwt.token"},
+        )
+        assert resp.status_code == 401
+        assert "Invalid or expired refresh token" in resp.json()["detail"]
+
+    def test_refresh_empty_body(self):
+        """Missing refresh_token field returns 422 validation error."""
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/refresh",
+            json={},
+        )
+        assert resp.status_code == 422
+
+    def test_refresh_missing_field(self):
+        """No body at all returns 422."""
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/refresh",
+            content="{}",
+            headers={"Content-Type": "application/json"},
+        )
+        assert resp.status_code == 422
+
+    def test_refresh_with_login_token(self):
+        """A refresh token obtained from login also works for /refresh."""
+        client = TestClient(app)
+        # Register first
+        client.post(
+            "/api/auth/register",
+            json={
+                "username": "refep_loginrefuser",
+                "email": "loginref@example.com",
+                "password": "secret123",
+                "date_of_birth": "2000-01-01",
+            },
+        )
+        # Login to get a refresh token
+        login_resp = client.post(
+            "/api/auth/login",
+            data={"username": "refep_loginrefuser", "password": "secret123"},
+        )
+        assert login_resp.status_code == 200
+        refresh_token = login_resp.json()["refresh_token"]
+
+        # Use it to refresh
+        resp = client.post(
+            "/api/auth/refresh",
+            json={"refresh_token": refresh_token},
+        )
+        assert resp.status_code == 200
+        assert "access_token" in resp.json()
+
+    def test_refresh_access_token_is_valid_jwt(self):
+        """The access token returned by /refresh is a valid JWT."""
+        from jose import jwt
+
+        refresh_token = self._register_user("refep_jwttoken", "secret123")
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/refresh",
+            json={"refresh_token": refresh_token},
+        )
+        assert resp.status_code == 200
+        access_token = resp.json()["access_token"]
+
+        # Verify it's a 3-part JWT
+        parts = access_token.split(".")
+        assert len(parts) == 3
+
+        # Verify it decodes with the public key
+        payload = jwt.decode(
+            access_token,
+            settings.public_pem,
+            algorithms=[settings.ALGORITHM],
+        )
+        assert "sub" in payload
+        assert "exp" in payload
+
+    def test_refresh_expires_minutes_in_response(self):
+        """The response includes access_token_expires_minutes."""
+        refresh_token = self._register_user("refep_expiretest", "secret123")
+        client = TestClient(app)
+        resp = client.post(
+            "/api/auth/refresh",
+            json={"refresh_token": refresh_token},
+        )
+        assert resp.status_code == 200
+        assert "access_token_expires_minutes" in resp.json()
+        assert resp.json()["access_token_expires_minutes"] == settings.ACCESS_TOKEN_EXPIRE_MINUTES

backend/tests/test_refresh_token_jti.py

@@ -0,0 +1,79 @@
+"""Tests for refresh token uniqueness (jti claim) and model column length."""
+
+import uuid
+from datetime import datetime, timedelta, timezone
+
+import pytest
+from jose import jwt
+
+from app.config import settings
+from app.routers.auth import _create_refresh_token
+from app.models.session import RefreshToken
+
+
+class TestRefreshTokenJtiUniqueness:
+    """Verify that _create_refresh_token produces unique tokens even when
+    called with identical data in rapid succession (issue #1 from review)."""
+
+    def test_two_calls_produce_different_tokens(self):
+        """Two calls with the same sub produce different JWTs because of jti."""
+        token_a = _create_refresh_token({"sub": "42"})
+        token_b = _create_refresh_token({"sub": "42"})
+        assert token_a != token_b
+
+    def test_jti_is_valid_uuid(self):
+        """The jti claim inside the refresh token is a valid UUID."""
+        token = _create_refresh_token({"sub": "1"})
+        payload = jwt.decode(
+            token,
+            settings.public_pem,
+            algorithms=[settings.ALGORITHM],
+        )
+        assert "jti" in payload
+        # Verify it parses as a UUID (raises ValueError if not)
+        uuid.UUID(payload["jti"])
+
+    def test_each_token_has_unique_jti(self):
+        """Generate 100 tokens for the same user — all jtis must differ."""
+        jtis = set()
+        for _ in range(100):
+            token = _create_refresh_token({"sub": "999"})
+            payload = jwt.decode(
+                token,
+                settings.public_pem,
+                algorithms=[settings.ALGORITHM],
+            )
+            jtis.add(payload["jti"])
+        assert len(jtis) == 100
+
+    def test_jti_survives_decode(self):
+        """The jti claim is present and correct after decode."""
+        token = _create_refresh_token({"sub": "7"})
+        payload = jwt.decode(
+            token,
+            settings.public_pem,
+            algorithms=[settings.ALGORITHM],
+        )
+        assert payload["sub"] == "7"
+        assert "jti" in payload
+        assert "exp" in payload
+
+
+class TestRefreshTokenModelColumnLength:
+    """Verify the model's token column length matches the migration (issue #2)."""
+
+    def test_token_column_has_length_512(self):
+        """RefreshToken.token column should be String(512), not unbounded."""
+        from sqlalchemy import inspect
+
+        # Get the column definition from the model's table
+        column = RefreshToken.__table__.columns["token"]
+        # The type should be String with length 512
+        assert column.type.length == 512
+
+    def test_token_column_type_is_string(self):
+        """The token column should be a String type."""
+        from sqlalchemy import String as SAString
+
+        column = RefreshToken.__table__.columns["token"]
+        assert isinstance(column.type, SAString)

docs/architecture/editor.md

@@ -0,0 +1,369 @@
+# Editor Architecture: Godot Editor Plugin vs. In-Game Editor
+
+> **Status:** Proposed
+> **Owner:** Platform team
+> **Related:** World chunk data format & persistence, server authority + client
+> prediction, content moderation & age verification, avatar component system
+> **Godot version:** 4.6.2 stable
+
+## 1. Overview
+
+This document evaluates the two primary ways to build the **world/level
+authoring tool** for **agp-game**:
+
+- **(a) Godot editor plugin** — extend the Godot editor itself with custom
+  panels, dock widgets, and tools that operate on the project's scenes and
+  resources.
+- **(b) In-game editor** — a fully custom editor built as game UI (Godot
+  `Control` nodes) that runs inside the running game, editing the game's own
+  world data.
+
+The goal is to pick the approach that best fits the platform's constraints:
+a **server-authoritative** multiplayer game where the **world is stored as
+versioned chunks** (see `world.md`), content is **moderation-flagged** (see
+`content_moderation.md`), and the client is a **shipped binary** that players
+run (not a dev tool).
+
+This document is a **decision record**: it lays out the trade-offs, gives a
+clear recommendation, and defines the resulting architecture boundaries.
+
+---
+
+## 2. Context & Constraints
+
+Before comparing the two approaches, we must fix the constraints that drive the
+decision. These come from the existing architecture docs.
+
+### 2.1 The World Is Data, Not Scenes
+
+`world.md` defines the world as **chunk data** (JSON for authoring, binary for
+runtime/network), persisted in SQLite on the server. A chunk is the atomic unit
+of load, save, and stream. The **server is the only writer** to the store;
+clients submit **deltas** against a `base_revision` and the server validates and
+applies them.
+
+**Implication:** The editor's output is **chunk payloads**, not `.tscn` scene
+files. Whatever editor we build must serialize to the chunk contract, not to
+Godot scene resources.
+
+### 2.2 Server-Authoritative & Moderation-Aware
+
+- The server validates every edit (schema, bounds, moderation) before
+  persisting (`world.md` §5.4).
+- Content carries **content flags** aggregated from referenced assets/scripts
+  (`content_moderation.md` §3). Mature content is gated behind age verification.
+- The client receives a **content manifest** and never loads content not in it.
+
+**Implication:** An editor that runs on a **player's machine** cannot be the
+authority on what gets published. Editing must go through the server's
+validation pipeline, and the editor must surface moderation flags.
+
+### 2.3 The Client Is a Shipped Binary
+
+The game is a multiplayer product. Players run a **release build**. The Godot
+editor is a **development tool** that players do not have.
+
+**Implication:** If authoring is a first-class *player* feature (user-generated
+content), the editor must ship inside the game binary. If authoring is a
+*developer/platform* feature, it can live in the editor.
+
+### 2.4 Two Distinct Audiences
+
+The evaluation must separate two audiences, because they have opposite needs:
+
+| Audience | Who | Where they run | What they build |
+|----------|-----|----------------|-----------------|
+| **Platform/dev** | The team building the game | Godot editor (dev machines) | Base worlds, rooms, templates, test levels |
+| **Players (UGC)** | End users | The shipped game | Their own rooms/worlds, published to the server |
+
+The two approaches map cleanly onto these audiences, and the right answer is
+likely **both** — but with a clear primary recommendation.
+
+---
+
+## 3. Approach (a): Godot Editor Plugin
+
+### 3.1 What It Is
+
+A Godot editor plugin is a set of scripts (and optionally scenes) that extend
+the editor via the `EditorPlugin` API. It can add:
+
+- **Dock panels** (`add_control_to_dock`) — e.g., a chunk/tile palette panel.
+- **Toolbar buttons** (`add_control_to_container`).
+- **Inspector plugins** (`EditorInspectorPlugin`) — custom property editors.
+- **Import plugins** (`EditorImportPlugin`) — custom asset importers.
+- **Scene/Node plugins** (`EditorNode3DGizmoPlugin`) — custom gizmos.
+- **Menu entries** (`add_tool_menu_item`).
+
+Plugins are enabled per-project via `project.godot` (`[editor_plugins]`).
+
+### 3.2 Pros
+
+- **Full editor power for free:** You get the scene tree, inspector, viewport
+  navigation, undo/redo, gizmos, and asset pipeline — all battle-tested.
+- **Native Godot editing:** Editing `.tscn` scenes, materials, and nodes is
+  exactly what the editor is built for. Great for authoring **base content**
+  (rooms, templates, avatar base bodies).
+- **Fast iteration for devs:** The platform team can build and test levels
+  directly in the tool they already use.
+- **Undo/redo, selection, snapping** come from the editor's `EditorUndoRedoManager`.
+- **No runtime footprint:** Editor-only code is stripped from export builds
+  (`@tool` scripts and editor plugins are not shipped to players).
+
+### 3.3 Cons
+
+- **Not available to players.** Players don't run the Godot editor. Any
+  player-facing UGC authoring cannot use this approach.
+- **Tied to the editor's UX.** You inherit the editor's look and interaction
+  model; deep customization is limited by what the editor API exposes.
+- **Editor API churn.** `EditorPlugin` APIs change between Godot versions;
+  plugins are more brittle across upgrades than game code.
+- **Scene-centric, not data-centric.** The editor is optimized for scenes and
+  resources. Our world is **chunk data** (`world.md`). We'd have to build a
+  translation layer (scene ↔ chunk) and keep it in sync — a real source of
+  drift.
+- **Single-user, local.** The editor edits local files. It does not natively
+  talk to our server-authoritative chunk store or the moderation pipeline.
+- **Headless/CI friction.** Validating plugin behavior in CI requires running
+  the editor headless, which is heavier than testing game code.
+
+### 3.4 Fit for Our Constraints
+
+- **Platform/dev authoring:** Excellent. This is the natural home for building
+  base worlds, rooms, and templates.
+- **Player UGC:** Not applicable. Players cannot run the editor.
+- **Server-authoritative chunk store:** Poor fit natively. The editor edits
+  local scenes; we'd bolt on a chunk export/import and a server sync layer.
+
+---
+
+## 4. Approach (b): In-Game Editor
+
+### 4.1 What It Is
+
+A fully custom editor built as **game UI** — Godot `Control` nodes (panels,
+buttons, toolbars) that run inside the running game. It edits the game's own
+world data model (chunks) and submits edits through the normal server pipeline.
+
+### 4.2 Pros
+
+- **Ships to players.** The editor is part of the game binary, so **player UGC
+  authoring is possible** — the core requirement for a user-generated-content
+  platform.
+- **Data-native.** The editor operates directly on the **chunk model**
+  (`world.md`), so there is no scene↔chunk translation layer and no drift.
+- **Server-authoritative by construction.** Edits go through the same
+  `request_chunk_edit` RPCs as gameplay, so validation, revisioning, and
+  moderation apply uniformly. The editor cannot bypass the server.
+- **Moderation-aware.** Because edits flow through the server, content flags are
+  computed and enforced at the boundary (`content_moderation.md` §4). The editor
+  can surface flags and gate mature content.
+- **One codebase, one UX.** The editor uses the same UI toolkit and art style as
+  the game; no separate editor theme to maintain.
+- **Testable in CI.** The editor is ordinary game code; it can be exercised
+  headlessly and unit-tested like any other system.
+
+### 4.3 Cons
+
+- **We build everything.** No free scene tree, inspector, gizmos, or undo/redo.
+  We must implement selection, snapping, undo/redo, viewport navigation, and
+  property editing ourselves.
+- **Runtime footprint.** Editor UI ships in the binary (though it can be gated
+  behind a feature flag / separate scene that is only instantiated on demand).
+- **More upfront work.** A usable in-game editor is a large feature; it needs
+  its own architecture (tool modes, gizmos, palette, inspector).
+- **Not ideal for deep asset authoring.** Modeling a mesh or authoring a
+  material is better done in the Godot editor / DCC tools. The in-game editor
+  should focus on **world composition** (placing tiles and objects), not asset
+  creation.
+
+### 4.4 Fit for Our Constraints
+
+- **Platform/dev authoring:** Workable but not ideal for deep asset work.
+- **Player UGC:** The **only** viable approach. Players can only author through
+  the shipped game.
+- **Server-authoritative chunk store:** Excellent fit. The editor is a client
+  that submits validated deltas.
+
+---
+
+## 5. Comparison Matrix
+
+| Criterion | (a) Editor plugin | (b) In-game editor |
+|-----------|-------------------|--------------------|
+| Ships to players | ❌ No | ✅ Yes |
+| Player UGC authoring | ❌ Impossible | ✅ Core capability |
+| World data model fit | ⚠️ Scene-centric; needs translation layer | ✅ Chunk-native |
+| Server-authoritative edits | ⚠️ Bolted on | ✅ Native (same RPCs) |
+| Moderation enforcement | ⚠️ Manual | ✅ At the boundary |
+| Free editor features (undo, gizmos, inspector) | ✅ Rich | ❌ Build ourselves |
+| Runtime footprint | ✅ None (stripped from export) | ⚠️ Ships in binary (gated) |
+| Dev iteration speed | ✅ Fast | ⚠️ Slower to build |
+| Deep asset authoring (mesh/material) | ✅ Native | ❌ Out of scope |
+| CI testability | ⚠️ Heavier (headless editor) | ✅ Ordinary game code |
+| Editor API churn risk | ⚠️ Higher | ✅ None (game code) |
+
+---
+
+## 6. Recommendation
+
+**Primary recommendation: build the in-game editor (b) as the platform's
+authoring surface, and use a lightweight Godot editor plugin (a) only as an
+internal dev convenience.**
+
+### 6.1 Rationale
+
+1. **Player UGC is the deciding factor.** The platform's value proposition is
+   user-generated content (rooms, worlds, avatars). Players cannot run the Godot
+   editor, so **only an in-game editor can deliver player authoring**. This is a
+   hard requirement that the editor-plugin approach cannot meet.
+
+2. **The world is data, and the in-game editor is data-native.** `world.md`
+   defines chunks as the atomic unit. An in-game editor edits chunks directly
+   and submits them through the server pipeline. An editor plugin would force a
+   scene↔chunk translation layer that is a constant source of drift and bugs.
+
+3. **Server authority and moderation fall out naturally.** Because in-game
+   edits use the same `request_chunk_edit` RPCs as gameplay, validation,
+   revisioning, optimistic concurrency, and content-flag enforcement
+   (`content_moderation.md`) apply uniformly. The editor cannot bypass the
+   server — which is exactly what a moderation-aware UGC platform needs.
+
+4. **The editor-plugin's strengths are not what we need.** Its free features
+   (scene tree, inspector, gizmos) are for editing Godot scenes and resources.
+   Our authoring is world composition against a chunk contract, not scene
+   editing. The plugin's main win — deep asset authoring — is better served by
+   DCC tools and the Godot editor for the *platform team*, not by a plugin we
+   must maintain.
+
+### 6.2 The Role of the Editor Plugin (Dev Convenience Only)
+
+We still recommend a **small, optional** editor plugin for the **platform team**
+to author **base content** (base rooms, templates, avatar base bodies, test
+levels) directly in the Godot editor. This is a dev-time convenience, not a
+product feature:
+
+- It can export a scene/resource as a **chunk** (reusing the same encoder as the
+  in-game editor) so dev-authored content flows into the same pipeline.
+- It is **not shipped** to players and is **not** the authoring surface for UGC.
+- It should be kept thin to minimize editor-API churn risk.
+
+### 6.3 Scope Boundary
+
+To keep the in-game editor tractable, define its scope clearly:
+
+- **In scope (world composition):** placing tiles, placing static/dynamic
+  objects, setting transforms, editing object properties, saving/loading chunks,
+  submitting edits to the server, showing moderation flags.
+- **Out of scope (asset creation):** modeling meshes, authoring materials,
+  rigging avatars. These are done in DCC tools / the Godot editor and imported
+  as catalog assets (see `avatar.md` §7). The in-game editor **references**
+  catalog assets by id; it does not create them.
+
+---
+
+## 7. Resulting Architecture
+
+### 7.1 Shared Editor Core
+
+Both the in-game editor and the (optional) dev plugin should share a single
+**editor core** that operates on the chunk model. This avoids two divergent
+implementations.
+
+```
+EditorCore (shared, data-native)
+├── ChunkEditorModel      # in-memory chunk being edited (tiles, objects, flags)
+├── ChunkEncoder          # JSON/binary encode/decode (world.md §3)
+├── EditSession           # base_revision tracking, delta generation
+├── EditSubmitter         # request_chunk_edit RPC wrapper + conflict handling
+├── UndoRedoStack         # command pattern over chunk mutations
+├── SelectionManager      # selected tiles/objects
+├── ToolRegistry          # brush, object-place, select, erase, etc.
+└── ModerationView        # surfaces content flags; gates mature content
+```
+
+### 7.2 In-Game Editor (Primary)
+
+```
+InGameEditor (Control-based UI, shipped in binary, gated by feature flag)
+├── EditorViewport        # custom 2D/3D viewport with camera navigation
+├── Toolbar               # tool mode switcher
+├── PalettePanel          # tile/object palette (from catalog)
+├── InspectorPanel        # property editor for selected object
+├── ChunkBrowser          # load/save chunks, list rooms
+└── EditorCore            # shared core (above)
+```
+
+- Instantiated only when the player enters "build mode" (a separate scene /
+  feature flag), so the runtime footprint is negligible during normal play.
+- Submits edits via `request_chunk_edit`; handles `chunk_edit_result` conflicts
+  by re-fetching and re-applying (`world.md` §5.4).
+
+### 7.3 Dev Editor Plugin (Optional, Thin)
+
+```
+DevChunkPlugin (EditorPlugin, dev-only, not shipped)
+├── Dock panel: "Chunk Export"
+├── Reads the current scene / selected nodes
+├── Maps scene content → chunk model (via EditorCore.ChunkEncoder)
+└── Exports a .chunk.json / submits to a dev server
+```
+
+Kept thin to minimize editor-API churn. Its only job is to let the platform team
+author base content in the editor and push it into the same chunk pipeline.
+
+### 7.4 Data Flow
+
+```
+[In-game editor]  --request_chunk_edit(delta, base_revision)-->  [Server]
+        ^                                                          | validate
+        |                                                          | apply
+        +--chunk_edit_result(ok/new_revision | conflict)-----------| persist
+                                                                   v
+                                                              SQLite (world.db)
+
+[Dev plugin]  --export chunk JSON-->  [EditorCore.ChunkEncoder]  -->  [Server]
+```
+
+Both paths converge on the **same server validation pipeline**, so moderation
+and revisioning are uniform regardless of authoring surface.
+
+---
+
+## 8. Risks & Mitigations
+
+| Risk | Mitigation |
+|------|------------|
+| In-game editor is a large build | Scope it to world composition (§6.3); reuse EditorCore; ship behind a feature flag |
+| Custom viewport/gizmos are hard | Start with a 2D tile editor (matches `CHUNK_SIZE_Z=1` default); add 3D later |
+| Undo/redo complexity | Use a command pattern over chunk mutations; test headlessly |
+| Editor-plugin API churn | Keep the plugin thin; treat it as dev-only convenience, not a product surface |
+| Drift between dev plugin and in-game editor | Both use the same `EditorCore`/`ChunkEncoder` |
+| Players bypass moderation | Impossible by construction: edits go through server validation |
+
+---
+
+## 9. Open Questions / Future Work
+
+- **3D editing:** The default world is flat (`CHUNK_SIZE_Z=1`). A 3D in-game
+  editor (volumetric chunks) is future work (`world.md` §8).
+- **Collaborative editing:** Multiple players editing the same chunk concurrently
+  — the optimistic-concurrency model already supports it, but the UX (live
+  cursors, conflict resolution) is unspecified.
+- **Template library:** A curated set of room templates players can start from.
+- **Publish/review flow:** How a player's authored room enters the moderation
+  review queue (`content_moderation.md` §6) and becomes publicly joinable.
+
+---
+
+## 10. Summary
+
+| Concern | Decision |
+|---------|----------|
+| Primary authoring surface | **In-game editor** (ships to players, enables UGC) |
+| Dev authoring convenience | Thin, optional **editor plugin** (not shipped) |
+| World data model | Both operate on the **chunk model** via a shared `EditorCore` |
+| Server authority | Edits go through `request_chunk_edit`; server validates |
+| Moderation | Enforced at the server boundary for both paths |
+| In-game editor scope | World composition only; asset creation is out of scope |
+| Runtime footprint | Editor gated behind a feature flag / separate scene |

docs/architecture/scripting_sandbox.md

@@ -0,0 +1,159 @@
+# GDScript Sandboxing for User-Written Scripts
+
+> **Status:** Proposed
+> **Owner:** Platform team
+> **Related:** Content moderation & age verification (scripts are one of the
+> three moderated content types), avatar component system
+
+## 1. Overview
+
+This document evaluates how to safely run **user-written scripts** as part of
+UGC (user-generated content) in **agp-game**, and recommends an approach.
+
+**Bottom line: Godot 4 has no built-in security sandbox for GDScript, and
+none of the three options named in the original task hold up under testing.**
+A script running anywhere inside the Godot process — however it's loaded,
+parented, or wrapped — runs with full engine privileges: arbitrary process
+execution, full filesystem read/write, and raw network access. Sandboxing
+has to happen *outside* the scripting language, not through an in-engine
+restriction mechanism, because no such mechanism exists.
+
+This was verified directly against Godot 4.6.2 (`godot --headless`, evidence
+in `sandbox_probe/` on this branch) rather than assumed from documentation,
+some of which (see §2.1) describes APIs that don't actually exist in this
+version.
+
+## 2. Options Evaluated
+
+### 2.1 Godot's built-in "ScriptServer" restrictions — does not exist
+
+There is no `ScriptServer` class in Godot 4.6.2:
+
+```
+ClassDB.class_exists("ScriptServer")  →  false
+```
+
+There's also no project setting to disable engine subsystems for scripts —
+none of `application/run/disable_os`, `disable_file_access`, or
+`disable_network` exist as settings, and `ProjectSettings.get_property_list()`
+returns nothing matching "sandbox", "restrict", or "security". Any plan that
+assumes a flag like this exists needs to be dropped; it was likely conflated
+with sandboxing features from a different engine/scripting ecosystem, or
+with **export template stripping** (which controls what ships in a build,
+not what a script can call at runtime).
+
+Directly probed capabilities of an ordinary GDScript running as a normal
+node script, no special setup:
+
+| Capability | Available to any script? |
+|---|---|
+| `OS.execute(...)` — run arbitrary processes | ✅ Yes |
+| `FileAccess.open(...)` — read/write any path the OS user can reach | ✅ Yes (read `/etc/hostname`, write `/tmp/...` both succeeded) |
+| `TCPServer` / `HTTPClient` / `HTTPRequest` / `PacketPeerUDP` / `WebSocketPeer` | ✅ All instantiate and work |
+| `ClassDB.instantiate(...)` — construct any engine class by name | ✅ Yes |
+| Loading and running a second script from source text at runtime (`GDScript.new()` + `.reload()`) | ✅ Yes |
+
+**Verdict: rejected.** There is nothing to configure here — the restriction
+surface this option assumed doesn't exist in the engine.
+
+### 2.2 Isolated SubViewport with a limited API — doesn't isolate scripts
+
+`SubViewport` is a **rendering and input isolation** primitive (it gives a
+scene subtree its own render target and can gate input propagation) — it is
+not a security or scripting boundary. A script attached to any node inside a
+`SubViewport` still runs in the same process, on the same GDScript VM, with
+the exact same access to `OS`, `FileAccess`, networking classes, and
+`ClassDB` as a script anywhere else in the tree. Nothing about being
+"inside" a SubViewport changes what API calls are reachable from a script.
+
+**Verdict: rejected.** This solves a rendering/UI-composition problem, not
+the security problem the task is asking about. Worth keeping in mind for
+other purposes (e.g. isolated preview rendering of user avatars), but it
+provides zero script sandboxing.
+
+### 2.3 Custom GDScript interpreter with an allowlist — right idea, wrong layer for "custom interpreter"
+
+Two ways to read this option, tested separately:
+
+**(a) Write/embed a separate GDScript parser+interpreter.** Not
+practical — this means re-implementing (and then indefinitely maintaining,
+in lockstep with every Godot release) a full language interpreter outside
+the engine. Far more engineering than the problem justifies.
+
+**(b) Use Godot's built-in `Expression` class as a restricted subset.**
+`Expression` *looks* like a natural allowlist mechanism — it only evaluates
+a single expression, no control flow, no arbitrary statements. But it isn't
+safe by default: it can still reach through to unsafe engine methods if you
+aren't careful about what object you hand it as a base instance:
+
+```gdscript
+var expr = Expression.new()
+expr.parse("get_environment('HOME')", ["OS"])
+expr.execute([], OS)   # → "/home/daddy"  (successfully called OS.get_environment)
+```
+
+So `Expression` is a viable building block only if the host **never passes
+a base instance (or arguments) that exposes anything sensitive** — i.e. the
+allowlisting work still has to happen at the call site, `Expression` itself
+enforces none of it.
+
+**Static text pattern-matching (blocklisting dangerous substrings like
+`"OS.execute"` before parsing) was also probed and is not a real
+defense** — it's trivially defeated by string concatenation, `call()`,
+`Callable`, or any other indirection, and produces false confidence.
+
+**Verdict: partially viable, but only as a foundation, not a solution on
+its own.** A hand-built, narrow, data-driven DSL (not full GDScript, not
+raw `Expression`) with an explicit allowlist of safe operations and *no
+ability to reference engine singletons or arbitrary objects* is the only
+version of "custom interpreter" that's actually safe. This is real
+engineering effort, not a config flag.
+
+## 3. Recommendation
+
+**Don't run untrusted GDScript in-process at all.** Given none of the three
+in-engine options provide a real boundary, the two approaches actually worth
+building are, in order of recommended priority:
+
+1. **Primary: a narrow, non-Turing-complete content DSL**, not general
+   scripting. Most UGC scripting needs in a game like this (custom
+   interactions, simple triggers, item behaviors) don't need a general
+   programming language — they need a small set of declarative
+   verbs/conditions (e.g. `on_interact: give_item("torch")`,
+   `on_enter: play_sound("chime")`). Expressed as data (JSON/Resource, not
+   code) and interpreted by trusted, hand-written GDScript on the engine
+   side. This has *zero* attack surface by construction — there's no
+   interpreter to escape because there's no general execution, just a
+   fixed, reviewed set of verbs. This is almost certainly sufficient for
+   the actual UGC use cases in this game and should be scoped against real
+   feature requirements before assuming more is needed.
+
+2. **If genuinely general scripting becomes a hard requirement**, isolate it
+   at the OS level, not the engine level: run untrusted scripts in a
+   **separate process** (a stripped-down Godot instance or a dedicated
+   interpreter) under OS sandboxing (a restricted user account, a
+   container, or `firejail`/`bwrap`/seccomp), communicating with the main
+   game over a narrow IPC/RPC boundary that only exposes intentionally-safe
+   operations. This is the only approach that provides a real security
+   boundary for arbitrary code, because it doesn't depend on the scripting
+   language cooperating — the OS enforces it. Substantially more
+   infrastructure than option 1; only worth it if option 1's DSL genuinely
+   can't express what's needed.
+
+**Do not** attempt in-process GDScript sandboxing via SubViewport,
+ScriptServer, or ad hoc blocklisting — all three were directly tested and
+none provide a real boundary (§2).
+
+## 4. Open Questions
+
+- What do actual planned UGC scripts need to *do*? (Trigger conditions,
+  simple item/state effects, dialogue branching?) This determines whether
+  the DSL in §3.1 is sufficient or whether §3.2's process isolation is
+  needed. Needs a concrete feature list before implementation starts.
+- If §3.2 is needed later, does it run per-user-session or shared/pooled?
+  Affects resource cost and isolation guarantees.
+- Interaction with the content moderation pipeline (`content_moderation.md`):
+  scripts as a moderated content type still need a moderation flag path
+  regardless of which execution model is chosen — a DSL makes static
+  analysis of *what a script can possibly do* far easier than it would be
+  for general code, which is an additional point in its favor.

docs/planning/client-server-wiring.md

@@ -0,0 +1,41 @@
+# MVP Vertical Slice: Client-Server Wiring — Plan
+
+## Goal
+Prove the real Godot client and the real backend can talk: **a user can register/log in
+and see a list of worlds from the game client**. Nothing more. Gameplay, join-a-world,
+chat, avatar, Discovery search/tags/trending, Social/Economy/Trust & Safety are all
+explicitly out of scope.
+
+## Verified backend contract (as of this writing)
+- `POST /api/auth/register` — JSON body `{username, email, password, date_of_birth}`.
+  `date_of_birth` is a `YYYY-MM-DD` string. Returns `201 {access_token, token_type}`.
+  Rejects under-18 with `400`.
+- `POST /api/auth/login` — OAuth2 **form-encoded** (`application/x-www-form-urlencoded`)
+  `username` + `password` (this is NOT a JSON endpoint). Returns `{access_token, token_type}`.
+- `GET /api/worlds` — **requires auth** (`CurrentUser`), returns a JSON array of
+  `{id, name, description, visibility, owner_id, created_at}`. There is no unauthenticated
+  public-worlds path, so the worlds list screen can only be shown after login/register.
+- `GET /api/health` — unauthenticated, `{status, app}`.
+- Base URL: uvicorn default `http://127.0.0.1:8000` (must be configurable in the client).
+- CORS is irrelevant to the native Godot `HTTPRequest` client (no browser origin).
+
+## Task breakdown
+| # | Type | Task | Depends on |
+|---|------|------|-----------|
+| 1 | architecture | `ApiClient` autoload: HTTP + JWT storage + error contract | — |
+| 2 | implementation | Main-menu **login + register** UI built & wired (form-encoded + JSON/age gate) | 1 |
+| 3 | implementation | **World list** screen consuming `GET /api/worlds` | 1 |
+| 4 | testing | End-to-end headless smoke test + manual verify | 1,2,3 |
+
+## Design decisions captured (resolved in task 1)
+- Token storage: in-memory singleton property for the MVP; a `save_to_disk` seam is left
+  open but not required yet (no re-login on restart in this slice).
+- Error contract: every call returns a discriminated result (`ok`/`error`) so callers
+  never crash on network failure; non-2xx surfaces `{status, detail}` from the backend.
+- Base URL: read from a ProjectSetting, defaulting to `http://127.0.0.1:8000`.
+- Login is form-encoded; register is JSON — the client helper must support both content types.
+
+## Notes
+- The main-menu auth UI does **not** exist yet (main_menu.gd currently has only Play/Quit
+  stubs). Task 2 must **build** the login/register UI, not merely wire an existing one.
+- The world-list screen also needs to be **built** (a new scene), not just wired.

docs/planning/economy.md

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+# Economy — Currency, Marketplace & Creator Payouts — Plan
+
+> **Status:** Planned
+> **Owner:** Platform team
+> **Feature ID:** `economy`
+> **Godot version:** 4.6.2 stable
+> **Backend:** FastAPI + SQLAlchemy (async) + PostgreSQL + Redis
+
+## 1. Overview
+
+This document breaks the **Economy** feature into user stories and right-sized
+implementation tasks. The feature delivers:
+
+- **Virtual currency ("Credits")** — a single, server-authoritative currency
+  with an immutable, append-only transaction ledger.
+- **Premium purchase** — buying Credits with real money through a pluggable
+  payment-provider hook.
+- **Marketplace** — user-generated content (UGC) listings where creators sell
+  items (assets, avatar items, experience passes) to players for Credits.
+- **Creator payouts** — accumulating creator earnings and paying them out to
+  external accounts through a pluggable payout-provider hook.
+- **Godot client** — wallet/transaction history, marketplace browse/buy/sell,
+  and creator payout screens.
+
+The economy is the monetization backbone of the platform. Because it moves
+virtual value between real people, correctness (no double-spend, no lost funds,
+no balance drift) and safety (fraud prevention, moderation, audit) are treated
+as **blocking requirements**, not add-ons.
+
+## 2. Why correctness is the differentiator
+
+The platform is a creator economy (players buy UGC from other players). The
+economy is the highest-risk surface after chat: a single arithmetic or
+concurrency bug can mint or destroy value and irreversibly erode trust.
+Correctness is therefore designed in from the start:
+
+- **One currency, integer units.** Credits are whole-number integers. There are
+  no floats, no rounding, and no client-computed totals.
+- **Append-only ledger.** Every balance change is a row in a `transactions`
+  table with a signed amount, a `balance_after` snapshot, a reference to the
+  event that caused it, and an **idempotency key** so retries cannot double
+  credit or double debit.
+- **Atomic, locked mutations.** Balance changes run in a single database
+  transaction with row locking (`SELECT ... FOR UPDATE`) so concurrent
+  purchases/payouts cannot race.
+- **Escrow hold.** Marketplace proceeds are held in `pending_escrow` for a
+  configurable window before becoming available to the seller, so fraudulent
+  or moderated sales can be reversed without clawing back paid-out funds.
+- **Server-authoritative fees.** The platform commission is computed
+  server-side from a configured rate; the client never supplies the fee or the
+  seller's net.
+
+## 3. Existing constraints (do not re-build)
+
+- **Auth:** JWT bearer tokens; `get_current_user` / `CurrentUser` dependency in
+  `app/dependencies.py`. All economy endpoints reuse this.
+- **DB:** async SQLAlchemy + Alembic; migration `0001_initial` is the head.
+  Existing tables: `users`, `sessions`, `worlds`, `assets`.
+- **Redis:** configured (`REDIS_URL`) but unused so far; adopted here for
+  idempotency short-caching and rate limiting.
+- **Models:** `User` (owner_id), `Asset` (owner_id, is_public, asset_type).
+  Marketplace items reference existing `assets` rows and/or avatar items.
+- **Content moderation:** `docs/architecture/content_moderation.md` defines
+  flag vocabulary, age gate, and moderation actions. Marketplace items and
+  listings must inherit and enforce these rules (see §7).
+- **Client:** Godot 4.6.2, minimal `main_menu.gd`; no economy UI yet.
+
+## 4. Key design decisions
+
+| Concern | Decision |
+|---|---|
+| Currency model | Single virtual currency **"Credits" (CR)**, integer units. One wallet row per user; no fractional amounts. |
+| Ledger | Append-only `transactions` table: signed `amount`, `balance_after`, `reference_type`/`reference_id`, unique `idempotency_key`. |
+| Concurrency | `SELECT ... FOR UPDATE` on the wallet row inside the mutation transaction; never read-modify-write from stale data. |
+| Payments | Pluggable `PaymentProvider` interface with a **no-op default** that simulates a confirmed payment for dev/testing (clearly flagged). Stripe/PayPal later. |
+| Marketplace items | `catalog_items` (what is sold) + `marketplace_listings` (a seller's offer with a price/status). One item can have multiple listings over time. |
+| Purchase flow | Atomic transaction: debit buyer → hold funds in escrow (`pending_escrow`) → grant item. Platform fee computed server-side. |
+| Escrow | Configurable hold window (default 72h) before `pending_escrow` becomes available seller earnings. Refunds during the window reverse the sale. |
+| Fees | Single configurable `MARKETPLACE_FEE_RATE` (default `0.30`). `seller_net = floor(price * (1 - fee_rate))`. |
+| Creator balance | `creator_balances` table: `available` (earned, payable), `pending` (inside an open payout request), `lifetime_earned`. Updated in the same transaction as the sale completion. |
+| Payouts | Pluggable `PayoutProvider.pay()` with a no-op default (simulated external ref). Minimum payout threshold, admin review for large payouts. |
+| Idempotency | Every money-moving request carries a client-generated `Idempotency-Key`; duplicate keys return the original result. |
+| Rate limiting | Redis token-bucket dependency reused from the social feature for purchase/listing/payout endpoints. |
+| Moderation | Listings enforce content flags + age gate; moderators can `delist`/`remove`; fraud/chargeback reversal is an audited admin action. |
+
+## 5. User stories
+
+### US-1 Currency & wallet
+As a player, I can see my Credit balance and transaction history, and the system
+credits/debits my wallet only through server-authoritative events.
+
+**Acceptance criteria**
+- Exactly one wallet per user, created lazily on first use.
+- Balance is always a non-negative integer; no operation can make it negative.
+- Every mutation appends an immutable ledger row with amount, resulting balance,
+  reference, and idempotency key.
+- Retrying a request with the same idempotency key does not double-apply.
+- `GET` endpoints expose current balance and paged transaction history.
+
+### US-2 Premium purchase (buy Credits)
+As a player, I can purchase Credits with real money and have them credited only
+after the payment is confirmed.
+
+**Acceptance criteria**
+- A purchase session is created through the payment provider (or the no-op
+  default) and is idempotent.
+- Credits are granted exactly once, only after a verified provider confirmation
+  (webhook/confirm endpoint), never on client claim.
+- Purchase amounts are bounded and server-defined; clients cannot pick arbitrary
+  prices.
+- Confirmation is idempotent and audited (provider reference recorded).
+
+### US-3 Marketplace listing (sell)
+As a creator, I can list a catalog item for sale at a Credit price and
+manage/remove my listings.
+
+**Acceptance criteria**
+- A listing references a valid `catalog_item` owned by the seller (or an
+  authorized seller).
+- Price is bounded (min/max) and set server-side; status transitions are
+  explicit (`active`, `sold`, `delisted`, `removed_by_moderation`).
+- Only the seller (or a moderator) can update/remove a listing.
+- Listings are searchable/filterable (item type, price range, owner).
+
+### US-4 Marketplace purchase (buy)
+As a player, I can buy a listed item. The purchase is atomic, holds funds in
+escrow, grants the item, and splits the payment between platform and seller.
+
+**Acceptance criteria**
+- A single transaction debits the buyer, holds funds in escrow, and grants the
+  item — no partial states on failure.
+- Platform fee and seller net are computed server-side from the configured rate.
+- After the escrow hold window, funds move from escrow to the seller's
+  available balance.
+- Refunds during the hold window reverse the sale and return funds to the buyer.
+- Concurrent purchases of a one-of-a-kind listing cannot both succeed.
+
+### US-5 Creator payouts
+As a creator, I can view my earned balance, request a payout, and track its
+status; admins can review and approve/reject payouts.
+
+**Acceptance criteria**
+- Available balance is derived only from completed (escrow-released) sales and
+  completed payouts; it never goes negative.
+- Payout requests are bounded (min threshold, max per period) and rate-limited.
+- Large payouts require admin review; all payout requests carry an audit trail
+  (requested by, reviewed by, provider reference, status).
+- The payout provider is called exactly once; idempotent on retry.
+
+### US-6 Godot client
+As a player, I can manage Credits, browse/buy/sell marketplace items, and manage
+payouts from the game UI.
+
+**Acceptance criteria**
+- An API client handles JWT auth, HTTP, and idempotency keys for all economy
+  calls.
+- Dedicated screens: wallet + transaction history, marketplace browse/buy,
+  sell-listing, and creator payout.
+- The client never computes balances, fees, or seller nets — it only displays
+  server responses.
+
+## 6. Task breakdown
+
+Right-sized to 1–3 files / one coherent piece of functionality each. Task IDs
+are sequential for dependency chaining.
+
+| # | Task | Story | Depends on |
+|---|------|-------|-----------|
+| 1 | Wallet & ledger models + Alembic migration (`wallets`, `transactions`) | US-1 | — |
+| 2 | Wallet service (atomic credit/debit, idempotency, locking) + wallet/transactions API | US-1 | 1 |
+| 3 | Premium purchase: `PaymentProvider` interface + purchase/confirm endpoints | US-2 | 1 |
+| 4 | Catalog item & listing models + migration (`catalog_items`, `marketplace_listings`, `creator_balances`) | US-3 | 1 |
+| 5 | Marketplace listing API (create/list/search/update/remove) | US-3 | 4 |
+| 6 | Marketplace purchase service + API (atomic escrow, fee split, item grant) | US-4 | 2, 4, 5 |
+| 7 | Creator payout request models + API (`payout_requests`) | US-5 | 2, 6 |
+| 8 | Payout admin review + `PayoutProvider` + audit | US-5 | 7 |
+| 9 | Marketplace moderation + content-flag/age-gate enforcement | cross-cutting | 5, 6 |
+| 10 | Godot economy API client (auth + HTTP + idempotency) | US-6 | 2 |
+| 11 | Godot wallet & transaction history UI | US-6 | 10 |
+| 12 | Godot marketplace browse/buy UI | US-6 | 6, 10 |
+| 13 | Godot selling & payout UI | US-6 | 5, 7, 10 |
+
+## 7. Phasing
+
+- **Phase 1 (currency + payments):** tasks 1–3. The foundation — ledger and
+  money movement must be rock-solid before anything spends Credits.
+- **Phase 2 (marketplace):** tasks 4–6. Listing and atomic purchase with escrow.
+- **Phase 3 (payouts):** tasks 7–8. Turn released escrow into creator payouts.
+- **Phase 4 (moderation):** task 9. Lock down the marketplace against mature
+  content and abuse.
+- **Phase 5 (client):** tasks 10–13, each landing after its backend dependency.
+
+## 8. Data model sketch
+
+```text
+wallets
+  id                bigint PK
+  user_id           int UNIQUE FK -> users.id
+  balance           bigint NOT NULL DEFAULT 0  CHECK (balance >= 0)
+  created_at        timestamptz
+  updated_at        timestamptz
+
+transactions        (append-only ledger)
+  id                bigint PK
+  wallet_id         bigint FK -> wallets.id
+  type              enum(credit_purchase, marketplace_purchase,
+                        marketplace_sale, escrow_release, payout,
+                        refund, admin_adjustment)
+  amount            bigint NOT NULL            (signed)
+  balance_after     bigint NOT NULL
+  reference_type    text                        (e.g. "purchase", "sale", "payout_request")
+  reference_id      text
+  idempotency_key   text UNIQUE
+  metadata_json     jsonb
+  created_at        timestamptz
+
+catalog_items
+  id                bigint PK
+  owner_id          int FK -> users.id
+  asset_id          int FK -> assets.id (nullable; null for non-asset virtual items)
+  item_type         enum(asset, avatar_item, experience_pass)
+  name              text
+  description       text
+  metadata_json     jsonb
+  created_at        timestamptz
+
+marketplace_listings
+  id                bigint PK
+  catalog_item_id   bigint FK -> catalog_items.id
+  seller_id         int FK -> users.id
+  price             bigint NOT NULL CHECK (price > 0)
+  status            enum(active, sold, delisted, removed_by_moderation)
+  created_at        timestamptz
+  updated_at        timestamptz
+
+purchases
+  id                bigint PK
+  listing_id        bigint FK -> marketplace_listings.id
+  buyer_id          int FK -> users.id
+  seller_id         int FK -> users.id
+  price             bigint NOT NULL
+  platform_fee      bigint NOT NULL
+  seller_net        bigint NOT NULL
+  status            enum(pending_escrow, completed, refunded, reversed)
+  escrow_hold_until timestamptz
+  created_at        timestamptz
+
+creator_balances
+  id                bigint PK
+  user_id           int UNIQUE FK -> users.id
+  available         bigint NOT NULL DEFAULT 0
+  pending           bigint NOT NULL DEFAULT 0
+  lifetime_earned   bigint NOT NULL DEFAULT 0
+  updated_at        timestamptz
+
+payout_requests
+  id                bigint PK
+  creator_id        int FK -> users.id
+  amount            bigint NOT NULL CHECK (amount > 0)
+  status            enum(pending, approved, paid, rejected)
+  external_ref      text
+  provider_ref      text
+  requested_by      int FK -> users.id
+  reviewed_by       int FK -> users.id (nullable)
+  reviewed_at       timestamptz
+  created_at        timestamptz
+```
+
+## 9. Security, anti-fraud & audit
+
+- **Server-authoritative balances/fees:** clients never compute totals; amounts
+  are validated server-side against bounds and the current listing.
+- **Row locking:** wallet and creator-balance mutations use `SELECT ... FOR
+  UPDATE` within one transaction.
+- **Idempotency:** every money-moving endpoint requires an `Idempotency-Key`;
+  duplicate keys return the stored original outcome.
+- **Rate limiting:** purchase, listing, and payout endpoints are token-bucket
+  rate-limited per user.
+- **Escrow & reversibility:** funds are not payable until the hold window
+  elapses; chargebacks/refunds reverse before release.
+- **Moderation:** listings carry the item's effective content flags; mature
+  items require age verification (per `content_moderation.md`); moderators can
+  `delist`/`remove` and trigger audited reversals.
+- **Audit:** the ledger plus `payout_requests` review fields form an append-only
+  audit trail for every movement of value.
+
+## 10. Out of scope for this feature
+
+- Real Stripe/PayPal/KYC integrations (provider interfaces leave the hooks; the
+  defaults are deterministic no-ops).
+- Subscriptions, recurring billing, or premium memberships.
+- Gift cards, promotional codes, or user-to-user Credit transfers.
+- Partial refunds, chargeback disputes, and seller tax/VAT handling.
+- In-world vending machines / scripted economy triggers (future, built on this
+  ledger via the scripting sandbox).

docs/planning/social.md

@@ -0,0 +1,170 @@
+# Social — Friends, Chat & Groups — Plan
+
+> **Status:** Planned
+> **Owner:** Platform team
+> **Feature ID:** `social`
+> **Godot version:** 4.6.2 stable
+> **Backend:** FastAPI + SQLAlchemy (async) + PostgreSQL + Redis
+
+## 1. Overview
+
+This document breaks the **Social** feature into user stories and right-sized
+implementation tasks. The feature delivers:
+
+- **Friends & following** — a friend request/accept model plus a one-way follow
+  relationship, with block lists.
+- **Presence & status** — online/offline, custom status message, last-seen.
+- **Chat** — direct messages (DM) and in-experience (world/room) chat with
+  **first-class safety**: server-side text filtering, report-message, and rate
+  limiting.
+- **Groups** — named groups with roles (owner/admin/member) and a simple group
+  page.
+- **Public profiles** — avatar, bio, favorite experiences, and a friends list
+  that respects privacy settings.
+
+## 2. Why chat safety is the differentiator
+
+The platform is explicitly meant to pull adults away from a youth-oriented
+competitor. Chat is the highest-risk surface: it is real-time, user-generated,
+and where abuse happens fastest. Safety is therefore treated as a **blocking
+requirement**, not an add-on:
+
+- Every message passes a **server-side text filter** before it is stored or
+  delivered. The client filter is cosmetic only; the server is authoritative.
+- Every message can be **reported**; reports flow into a moderation queue with
+  actor + reason + audit trail (mirroring `content_moderation.md`).
+- Sending is **rate limited** per user (Redis token bucket) to stop flooding and
+  harassment-by-volume.
+- Report and block are always reachable from a message context in the UI.
+
+## 3. Existing constraints (do not re-build)
+
+- **Auth:** JWT bearer tokens; `get_current_user` / `CurrentUser` dependency in
+  `app/dependencies.py`. All social endpoints reuse this.
+- **DB:** async SQLAlchemy + Alembic; migration `0001_initial` is the head.
+- **Redis:** configured (`REDIS_URL`) but unused so far; adopted here for
+  presence and rate limiting.
+- **Models:** `User`, `World` (owner_id), `Asset` (owner_id, is_public). Avatars
+  and favorite-experience references point at existing rows.
+- **Client:** Godot 4.6.2, minimal `main_menu.gd`; no social UI yet.
+
+## 4. Key design decisions
+
+| Concern | Decision |
+|---|---|
+| Message transport | REST for send/history; **WebSocket** gateway for real-time delivery + presence (matches `networking.md`'s "WebSocket as secondary transport" for chat) |
+| Presence store | Redis (TTL heartbeat) + persisted `last_seen_at` on the user record |
+| Text filtering | Pluggable `TextFilter` interface with a deterministic default (profanity list + normalization) so it runs without external services; third-party hook later |
+| Rate limiting | Redis token-bucket dependency, reusable across all social endpoints |
+| Reports | `message_reports` table + moderation endpoints (list/review/resolve) with audit fields |
+| Friends vs. follow | Friends = mutual (request→accept). Follow = one-way (no approval). Block = hard deny that also hides content and prevents DMs |
+| Privacy | Per-user settings JSON (`profile_visibility`, `friends_list_visibility`, `favorites_visibility`) enforced server-side on every read |
+| Groups | `groups` + `group_members` (role: owner/admin/member) + group page aggregate endpoint |
+| Real-time | One WebSocket endpoint multiplexing presence, DM, and world-chat messages via Redis pub/sub |
+
+## 5. User stories
+
+### US-1 Friends & following
+As a player, I can send a friend request, accept/decline incoming requests,
+unfriend, follow/unfollow other players, and block users so they can't interact
+with me.
+
+**Acceptance criteria**
+- Friend requests are one-directional until accepted; accepted friendships are mutual.
+- Follow is one-way and requires no approval.
+- Block prevents DMs, hides the blocked user's profile/friends interactions, and
+  removes any existing friendship/follow between the two.
+- Duplicate/self requests are rejected idempotently.
+
+### US-2 Presence & status
+As a player, I can see whether my friends are online, their custom status, and
+when they were last seen.
+
+**Acceptance criteria**
+- Online/offline is derived from a server-side heartbeat (Redis TTL), not client claims.
+- `last_seen_at` persists and is visible (subject to privacy settings).
+- Custom status text is optional and length-limited.
+
+### US-3 Public profiles
+As a player, I can view a public profile page showing avatar, bio, favorite
+experiences, and a friends list that respects the owner's privacy settings.
+
+**Acceptance criteria**
+- Avatar and bio are editable by the owner only.
+- Favorite experiences reference existing `World` rows.
+- A viewer sees only the sections the owner's privacy settings allow; blocked
+  users see a restricted view.
+
+### US-4 Chat (DM + in-experience) with safety
+As a player, I can send direct messages and chat inside a world/room. Messages
+are filtered, rate limited, and reportable.
+
+**Acceptance criteria**
+- Server filters message text before storing/delivering; filtered content is either
+  rejected (blocking) or redacted (configurable per filter policy).
+- Send rate is limited per user (token bucket); excess sends get `429`.
+- Every message has a stable id, author, timestamp, and conversation/world scope.
+- Any message can be reported with a reason; reports are stored and reviewable.
+- Real-time delivery over WebSocket with REST fallback for history.
+
+### US-5 Groups
+As a player, I can create a group, join/leave groups, and (as owner/admin)
+manage roles and view a simple group page.
+
+**Acceptance criteria**
+- Each group has exactly one owner and any number of admins/members.
+- Role transitions are authorized (only owner can transfer ownership or promote/demote admins).
+- Group page lists name, description, member list with roles, and member count.
+
+### US-6 Godot client
+As a player, I can access friends, presence, chat, profiles, and groups from the
+game UI.
+
+**Acceptance criteria**
+- An API client handles JWT auth, HTTP, and WebSocket for all social calls.
+- Dedicated screens/panels: friends+presence, DM & world chat (with report),
+  profile page, group page.
+- Client-side filtering is cosmetic; server responses remain authoritative.
+
+## 6. Task breakdown
+
+Right-sized to 1–3 files / one coherent piece of functionality each. Task IDs
+are sequential for dependency chaining.
+
+| # | Task | Story | Depends on |
+|---|------|-------|-----------|
+| 1 | Friends/follow/block models + Alembic migration | US-1 | — |
+| 2 | Friends & follow API router | US-1 | 1 |
+| 3 | Presence & status model + endpoints (Redis heartbeat) | US-2 | — |
+| 4 | Profile model + migration + own-profile endpoints | US-3 | 1 |
+| 5 | Public profile view + favorites + privacy enforcement | US-3 | 2, 4 |
+| 6 | Chat data models + migration (conversations, messages, reports) | US-4 | — |
+| 7 | Text filtering service + profanity config | US-4 | — |
+| 8 | Redis rate-limiting dependency | US-4 | — |
+| 9 | DM chat send/list endpoints (filter + rate limit) | US-4 | 6, 7, 8 |
+| 10 | Report-message endpoint + moderation queue | US-4 | 6, 9 |
+| 11 | In-experience (world/room) chat endpoints | US-4 | 9 |
+| 12 | Real-time WebSocket gateway (presence + DM + world chat) | US-4 | 3, 9, 11 |
+| 13 | Group + membership models + migration | US-5 | — |
+| 14 | Groups API (CRUD, join/leave, roles, group page) | US-5 | 13 |
+| 15 | Godot API client (auth + HTTP + WebSocket) | US-6 | 2 |
+| 16 | Godot friends & presence UI | US-6 | 3, 15 |
+| 17 | Godot chat UI (DM + world chat + report) | US-6 | 12, 15 |
+| 18 | Godot profile page UI | US-6 | 5, 15 |
+| 19 | Godot groups UI + group page | US-6 | 14, 15 |
+
+## 7. Phasing
+
+- **Phase 1 (data + core APIs):** tasks 1–5 (friends, presence, profiles).
+- **Phase 2 (chat safety — the differentiator):** tasks 6–12 (chat + safety +
+  realtime). This is the critical path and highest priority.
+- **Phase 3 (groups):** tasks 13–14.
+- **Phase 4 (client):** tasks 15–19, each landing after its backend dependency.
+
+## 8. Out of scope for this feature
+
+- Age verification / maturity gating (covered by `content_moderation.md`).
+- Voice chat, media/image messages, message editing/deletion history.
+- Third-party profanity/toxicity vendors (the `TextFilter` interface leaves a
+  hook, but the default is deterministic and dependency-free).
+- Mobile push notifications.

docs/testing/README.md

@@ -0,0 +1,50 @@
+# Testing at Package Checkpoints
+
+A Package Checkpoint (PC1, PC2, ...) is a periodic review point — every few
+real milestones, the client and server builds get packaged together and
+independently reviewed before anyone calls anything actually done. See
+`project_agp` in Claude's memory, or ask, for the full definition; this
+doc is just the mechanical "how do I run the tests" part of that review.
+
+## Running the suite
+
+```
+python scripts/run_checkpoint_tests.py
+```
+
+Brings up a throwaway Postgres, runs Alembic migrations against it, runs the
+backend pytest suite, starts the backend server, and runs every Godot
+headless smoke test (`scripts/smoke_test_*.gd`) against it. Tears the
+Postgres container down afterward (`--keep-postgres` to skip that if you
+want to poke at the DB after a failure).
+
+If port 5432 is already taken on the machine, pass `--postgres-port` with
+something else.
+
+Exit code is 0 only if everything that actually ran passed — suites with
+nothing to run yet (no Godot binary found, no smoke test scripts yet) are
+reported SKIPPED, not treated as a failure.
+
+## What this does and doesn't prove
+
+Passing this script means: migrations apply cleanly to a genuinely empty
+database, the backend's unit-level logic is correct, and whatever Godot
+smoke tests exist actually round-trip against a live backend. It does
+**not** mean full endpoint/integration coverage exists — see
+`test_inventory.md` for the current, honest list of what's tested and what
+isn't. A checkpoint review should still involve reading the actual diffs
+for anything this script's current coverage doesn't reach, not just running
+green and calling it done.
+
+## Growing this over time
+
+As real integration tests get added (endpoint tests hitting the FastAPI app,
+more Godot smoke coverage beyond `health_check`), they should land under
+`backend/tests/` / `scripts/smoke_test_*.gd` respectively — this script
+picks up new files automatically, nothing to register by hand. Update
+`test_inventory.md`'s tables when you do, so the inventory stays a source
+of truth instead of quietly going stale.
+
+Eventual goal (not implemented yet): gate merges to `main` on this script
+passing, the same way a real CI pipeline would. For now it's a manual step
+run at checkpoint review time.

docs/testing/test_inventory.md

@@ -0,0 +1,94 @@
+# Test Inventory
+
+What automated coverage actually exists, what it actually verifies, and what
+doesn't have coverage yet. Keep this current as tests are added — it's the
+thing a Package Checkpoint review (see `docs/testing/README.md`) reads first
+to know what "run the tests" actually checked.
+
+Run everything below in one shot with `scripts/run_checkpoint_tests.py`.
+
+Last verified against `main`: 2026-08-20 (commit `927f9bd`) — full PC1
+checkpoint run, fresh clone, migrations + pytest + all 4 Godot smoke tests +
+both platform exports, all clean.
+
+## Backend — `backend/tests/` (pytest)
+
+Run: `cd backend && python -m pytest -v` (needs `DATABASE_URL` pointed at a
+reachable Postgres — see the runner script).
+
+**Current total: 68 tests, all passing on a clean `main` checkout.**
+
+| File | Tests | What it covers |
+|---|---|---|
+| `test_auth_age_gate.py` | 17 | `calculate_age()` date-math correctness (exact boundary, leap years, birthday-not-yet-this-year) + `RegisterRequest` date-of-birth validation (parametrized valid/invalid date rejection). Backs the 18+ registration gate (PR #23). |
+| `test_gltf_metadata.py` | 21 | glTF/GLB binary + JSON parsing: magic-byte detection, chunk-padding handling, mesh/animation/texture-reference metadata extraction, malformed-input rejection. Backs the asset-import pipeline (PR #27). |
+| `test_auth_endpoints.py` | 11 | **Integration tests** for `POST /api/auth/register` and `POST /api/auth/login` against the real FastAPI app + real Postgres. Covers: successful register (201), duplicate username (409), duplicate email (409), underage rejection (400), invalid date format (422), exact-18 registration, successful login with correct credentials (200), wrong password (401), nonexistent user (401), form-encoded login (OAuth2), and JWT validity of returned tokens. |
+| `test_refresh_endpoint.py` | 8 | **Integration tests** for `POST /api/auth/refresh`. Covers: successful refresh (200, new access token, same refresh token returned), refresh produces different access tokens on repeated calls, invalid refresh token (401), empty body (422), missing field (422), refresh token from login also works, returned access token is valid JWT decodable with public key, `access_token_expires_minutes` in response. |
+| `test_refresh_token_jti.py` | 6 | Unit tests for refresh token uniqueness (jti claim) and model column length. Covers: two calls with same sub produce different tokens (jti uniqueness), jti is valid UUID, rapid repeated calls all produce unique jtis, jti survives decode, `RefreshToken.token` column is `String(512)`, column type is `String`. |
+| `test_auth_expired_token.py` | 5 | **Integration tests** for expired-token rejection across auth endpoints. Covers: expired access JWT rejected by `GET /api/auth/me` (401), garbage access token rejected by `/me` (401), missing bearer token returns 401, expired refresh token (DB `expires_at` in past) rejected by `/refresh` (401), expired refresh JWT (past `exp` claim) rejected before DB lookup (401). |
+
+**What these are, honestly:** a mix of pure unit tests (`test_auth_age_gate.py`,
+`test_gltf_metadata.py`, `test_refresh_token_jti.py`) and real integration tests
+(`test_auth_endpoints.py`, `test_refresh_endpoint.py`, `test_auth_expired_token.py`)
+that hit the FastAPI app against a real Postgres database via `TestClient`.
+The integration tests exercise the full stack: Pydantic validation → DB →
+JWT → response. The suite is also re-runnable without manual cleanup —
+`backend/tests/conftest.py` has a session-scoped autouse fixture that
+truncates all app tables once before the suite runs.
+
+**Known coverage gaps** (real gaps, not placeholders — nothing enforces filling
+these yet):
+- No endpoint tests for `GET /api/worlds`, `GET /api/assets/*`, or any
+  world/asset CRUD routes — only auth endpoints have integration coverage
+  (`GET /api/worlds` is covered indirectly via the Godot smoke tests below).
+- No tests for the moderation schema/migration beyond "the migration runs."
+- No tests for the `GET /api/auth/me` endpoint's response body (only its
+  auth-header validation is covered via expired-token tests).
+- No tests for session management (create/validate/revoke sessions).
+
+## Godot client — `scripts/smoke_test_*.gd`
+
+**4 smoke tests merged into `main`.** Each needs a live backend —
+`AGP_API_BASE_URL` env var, falling back to the
+`application/agp/api_base_url` project setting (default
+`http://127.0.0.1:8000`) if unset.
+
+| File | What it covers |
+|---|---|
+| `smoke_test_api.gd` | Exercises `ApiClient.health_check()` against a live backend. Verifies the real HTTP request path (`HTTPRequest` node lifecycle, JSON parse, result-dictionary contract). Exits 1 on failure. |
+| `smoke_test_auth.gd` | Tests the full auth flow via `ApiClient` autoload: register unique user (201), duplicate username (409), under-18 registration (400), correct login (200), wrong password (401), nonexistent user (401). |
+| `smoke_test_e2e.gd` | End-to-end flow: health check → register → login → worlds list. Verifies the full request chain with a fresh user, including token storage and `get_worlds()` with auth header. |
+| `smoke_test_world_list.gd` | Instantiates `world_list.tscn` as a real scene, adds to tree (catches `@onready` node-path bugs), waits for `_refresh_worlds()` to complete, confirms the screen reaches a real end state (world cards, empty-list message, or error label — not stuck loading). |
+
+Run (once, to build the class cache): `godot --headless --path . --import`,
+then for each smoke test: `godot --headless --path . --script
+res://scripts/smoke_test_<name>.gd` — **no `--quit`**, it kills these before
+their awaited HTTP calls finish.
+
+**Known gaps:**
+- No smoke tests for the main menu scene (`main_menu.tscn`).
+- No smoke tests for chunk loading/streaming (`chunk.gd`, `chunk_scene.gd`).
+- No smoke tests for dynamic/static object nodes.
+- All smoke tests require a live backend; no offline/unit smoke tests exist.
+- `smoke_test_world_list.gd` is the only one that exercises a real `.tscn`
+  scene instantiation — others only test the `ApiClient` autoload.
+- `get_me()` (`GET /auth/me`) is implemented in `scripts/api_client.gd` but
+  has no smoke coverage yet.
+
+## Client export
+
+`scripts/build.sh` produces real Linux (`agp-game.x86_64`) and Windows
+(`agp-game.exe`) binaries via `--export-release`. Verified 2026-08-20: both
+exports complete clean from a fresh checkout and produce valid binaries
+(confirmed via `file` — real ELF64/PE32+, not empty or truncated). Neither
+export is exercised by an automated GUI test (headless Godot can't drive a
+window) — actually launching and clicking through the exported binary is a
+manual step, see `docs/checkpoints/PC1.md` for playtest instructions.
+
+## What "full coverage" should eventually mean here
+
+Not defined precisely yet — the honest target as of 2026-08-20 is
+"integration tests for every endpoint + smoke tests for every major scene."
+As real integration/endpoint tests get added, update the tables above
+rather than letting this doc drift stale; a wrong inventory is worse than
+no inventory.

export_presets.cfg

@@ -0,0 +1,74 @@
+[preset.0]
+
+name="Linux"
+platform="Linux/X11"
+runnable=true
+advanced_options=false
+dedicated_server=false
+custom_features=""
+export_filter="all_resources"
+include_filter=""
+exclude_filter=""
+export_path="export/linux/agp-game.x86_64"
+encryption_include_filters=""
+encryption_exclude_filters=""
+encrypt_pck=false
+encrypt_directory=false
+script_export_mode=2
+
+[preset.0.options]
+
+custom_template/debug=""
+custom_template/release=""
+debug/export_console_wrapper=1
+binary_format/embed_pck=false
+texture_format/bptc=true
+texture_format/s3tc=true
+texture_format/etc=false
+texture_format/etc2=false
+binary_format/architecture="x86_64"
+ssh_remote_deploy/enabled=false
+
+[preset.1]
+
+name="Windows Desktop"
+platform="Windows Desktop"
+runnable=true
+advanced_options=false
+dedicated_server=false
+custom_features=""
+export_filter="all_resources"
+include_filter=""
+exclude_filter=""
+export_path="export/windows/agp-game.exe"
+encryption_include_filters=""
+encryption_exclude_filters=""
+encrypt_pck=false
+encrypt_directory=false
+script_export_mode=2
+
+[preset.1.options]
+
+custom_template/debug=""
+custom_template/release=""
+debug/export_console_wrapper=1
+binary_format/embed_pck=false
+texture_format/bptc=true
+texture_format/s3tc=true
+texture_format/etc=false
+texture_format/etc2=false
+binary_format/architecture="x86_64"
+codesign/enable=false
+application/icon=""
+application/console_wrapper_icon=""
+application/icon_interpolation=4
+application/file_version=""
+application/product_version=""
+application/company_name=""
+application/product_name=""
+application/file_description=""
+application/copyright=""
+application/trademarks=""
+application/export_angle=0
+application/export_d3d12=0
+d3d12/agility_sdk_multizip=0

project.godot

@@ -6,11 +6,22 @@ config_version=5
 
 [application]
 
-config/name="AGP Game"
+config/name="AGP-Game"
-run/main_scene="res://scenes/main.tscn"
+run/main_scene="res://scenes/main_menu.tscn"
 config/features=PackedStringArray("4.6.2")
+agp/api_base_url="http://127.0.0.1:8000"
+
+[autoload]
+
+ApiClient="*res://scripts/api_client.gd"
 
 [display]
 
-window/size/viewport_width=1280
+window/size/viewport_width=1920
-window/size/viewport_height=720
+window/size/viewport_height=1080
+window/stretch/mode="canvas_items"
+
+[rendering]
+
+renderer/rendering_method="gl_compatibility"
+renderer/rendering_method.mobile="gl_compatibility"

sandbox_probe/.godot/.gdignore

@@ -0,0 +1 @@
+

sandbox_probe/probe6.gd

@@ -0,0 +1,174 @@
+extends Node
+
+func _ready():
+	print("=== SANDBOX PROBE 6: Corrected Evidence Gathering (Godot 4.6.2) ===")
+	probe_script_loading()
+	probe_os_apis()
+	probe_file_access()
+	probe_network()
+	probe_classdb()
+	probe_expression_engine()
+	probe_engine_singletons()
+	probe_worker_threads()
+	probe_project_settings()
+	probe_allowlist()
+	print("=== SANDBOX PROBE 6 END ===")
+	get_tree().quit()
+
+func probe_script_loading():
+	print("--- Script loading ---")
+	var gd = GDScript.new()
+	gd.source_code = "extends RefCounted\nfunc hello():\n\treturn 42\n"
+	var err = gd.reload()
+	print("GDScript.reload() from source_code err=", err)
+	if err == OK:
+		var inst = gd.new()
+		print("  instantiated, hello()=", inst.call("hello"))
+	var res = load("res://test_script.gd")
+	print("load('res://test_script.gd') = ", res)
+	if res:
+		print("  get_source_code() available: ", res.has_method("get_source_code"))
+	print("  GDScript instance has 'get_ast': ", gd.has_method("get_ast"))
+	print("  GDScript instance has 'get_parser': ", gd.has_method("get_parser"))
+	print("  GDScript instance has 'get_script_method_list': ", gd.has_method("get_script_method_list"))
+	print("  GDScript instance has 'get_script_property_list': ", gd.has_method("get_script_property_list"))
+
+func probe_os_apis():
+	print("--- OS APIs ---")
+	var out = []
+	var exit_code = OS.execute("echo", ["hello"], out)
+	print("OS.execute('echo') exit=", exit_code, " out=", out)
+	print("OS.get_environment('HOME') = ", OS.get_environment("HOME"))
+	print("OS has 'create_process': ", OS.has_method("create_process"))
+	print("OS.get_cmdline_args() = ", OS.get_cmdline_args())
+	print("OS.get_user_data_dir() = ", OS.get_user_data_dir())
+	print("OS.get_executable_path() = ", OS.get_executable_path())
+
+func probe_file_access():
+	print("--- File access ---")
+	var f = FileAccess.open("/etc/hostname", FileAccess.READ)
+	print("FileAccess.open('/etc/hostname') = ", f)
+	if f:
+		print("  content: ", f.get_as_text())
+		f.close()
+	var w = FileAccess.open("/tmp/godot_probe_write.txt", FileAccess.WRITE)
+	print("FileAccess.open('/tmp/...', WRITE) = ", w)
+	if w:
+		w.store_string("probe")
+		w.close()
+		print("  wrote to /tmp OK")
+	var dir = DirAccess.open("/")
+	print("DirAccess.open('/') = ", dir)
+	if dir:
+		var names = dir.get_files()
+		print("  root files count: ", names.size())
+	var res_dir = DirAccess.open("res://")
+	print("DirAccess.open('res://') = ", res_dir)
+	var user_dir = DirAccess.open("user://")
+	print("DirAccess.open('user://') = ", user_dir)
+
+func probe_network():
+	print("--- Network ---")
+	var tcp = TCPServer.new()
+	var bind_err = tcp.listen(0)
+	print("TCPServer.listen(0) err=", bind_err)
+	var http = HTTPClient.new()
+	print("HTTPClient instantiated: ", http != null)
+	var http_req = HTTPRequest.new()
+	print("HTTPRequest instantiated: ", http_req != null)
+	var udp = PacketPeerUDP.new()
+	print("PacketPeerUDP instantiated: ", udp != null)
+	var ws = WebSocketPeer.new()
+	print("WebSocketPeer instantiated: ", ws != null)
+
+func probe_classdb():
+	print("--- ClassDB ---")
+	print("ClassDB.class_exists('OS'): ", ClassDB.class_exists("OS"))
+	print("ClassDB.class_exists('FileAccess'): ", ClassDB.class_exists("FileAccess"))
+	print("ClassDB.class_exists('TCPServer'): ", ClassDB.class_exists("TCPServer"))
+	print("ClassDB.class_exists('HTTPClient'): ", ClassDB.class_exists("HTTPClient"))
+	var class_list = ClassDB.get_class_list()
+	print("ClassDB.get_class_list() count: ", class_list.size())
+	var os_methods = ClassDB.class_get_method_list("OS")
+	print("OS method count: ", os_methods.size())
+	var inst = ClassDB.instantiate("Node")
+	print("ClassDB.instantiate('Node') = ", inst)
+	print("ClassDB has 'class_get_singleton': ", ClassDB.has_method("class_get_singleton"))
+
+func probe_expression_engine():
+	print("--- Expression engine ---")
+	var expr = Expression.new()
+	var err = expr.parse("1 + 2")
+	print("Expression.parse('1 + 2') err=", err)
+	if err == OK:
+		var result = expr.execute()
+		print("  Expression.execute() = ", result)
+	var expr2 = Expression.new()
+	err = expr2.parse("OS.get_environment('HOME')")
+	print("Expression.parse('OS.get_environment') err=", err)
+	if err == OK:
+		var result2 = expr2.execute()
+		print("  Expression.execute() = ", result2)
+	var expr3 = Expression.new()
+	err = expr3.parse("get_environment('HOME')", ["OS"])
+	print("Expression.parse with base_instance err=", err)
+	if err == OK:
+		var result3 = expr3.execute([], OS)
+		print("  Expression.execute with OS base = ", result3)
+	var expr4 = Expression.new()
+	err = expr4.parse("FileAccess.open('/etc/hostname', 1)")
+	print("Expression.parse('FileAccess.open') err=", err)
+	if err == OK:
+		var result4 = expr4.execute()
+		print("  Expression.execute() = ", result4)
+	var expr5 = Expression.new()
+	err = expr5.parse("get_tree().quit()")
+	print("Expression.parse('get_tree().quit()') err=", err)
+	if err == OK:
+		var result5 = expr5.execute()
+		print("  Expression.execute() = ", result5)
+
+func probe_engine_singletons():
+	print("--- Engine singletons ---")
+	print("Engine has 'remove_singleton': ", Engine.has_method("remove_singleton"))
+	print("Engine has 'add_singleton': ", Engine.has_method("add_singleton"))
+	print("Engine.get_main_loop() = ", Engine.get_main_loop())
+
+func probe_worker_threads():
+	print("--- Worker threads ---")
+	var thread = Thread.new()
+	print("  Thread.new() = ", thread)
+	print("  WorkerThreadPool has 'add_task': ", WorkerThreadPool.has_method("add_task"))
+
+func probe_project_settings():
+	print("--- Project settings ---")
+	var settings = ProjectSettings.get_property_list()
+	var relevant = []
+	for s in settings:
+		var name = String(s.name)
+		if "sandbox" in name.to_lower() or "restrict" in name.to_lower() or "security" in name.to_lower():
+			relevant.append(name)
+	print("  Sandbox/security project settings: ", relevant)
+	print("  ProjectSettings has 'application/run/disable_os': ", ProjectSettings.has_setting("application/run/disable_os"))
+	print("  ProjectSettings has 'application/run/disable_file_access': ", ProjectSettings.has_setting("application/run/disable_file_access"))
+	print("  ProjectSettings has 'application/run/disable_network': ", ProjectSettings.has_setting("application/run/disable_network"))
+	print("  ProjectSettings has 'set_setting': ", ProjectSettings.has_method("set_setting"))
+	print("  ProjectSettings has 'save': ", ProjectSettings.has_method("save"))
+
+func probe_allowlist():
+	print("--- Allowlist / static analysis ---")
+	var dangerous_patterns = [
+		"OS.execute", "OS.create_process", "OS.get_environment",
+		"FileAccess.open", "DirAccess.open", "TCPServer", "HTTPClient",
+		"load(", "preload(", "ClassDB", "Engine.get_main_loop",
+		"get_tree().quit", "ProjectSettings"
+	]
+	var test_script = """extends Node
+func _ready():
+	var f = FileAccess.open("/etc/passwd", FileAccess.READ)
+	OS.execute("rm", ["-rf", "/"])
+"""
+	print("  Test script contains dangerous patterns:")
+	for p in dangerous_patterns:
+		if p in test_script:
+			print("    DETECTED: ", p)

sandbox_probe/probe6.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://probe6.gd" id="1"]
+
+[node name="Probe6" type="Node"]
+script = ExtResource("1")

sandbox_probe/project.godot

@@ -0,0 +1,8 @@
+; Engine configuration file.
+config_version=5
+
+[application]
+
+config/name="sandbox_probe"
+run/main_scene="res://probe6.tscn"
+config/features=PackedStringArray("4.6")

sandbox_probe/test_script.gd

@@ -0,0 +1,4 @@
+extends RefCounted
+
+func hello():
+	return "from test_script.gd"

scenes/main_menu.tscn

@@ -0,0 +1,114 @@
+[gd_scene load_steps=2 format=3 uid="uid://main_menu_scene"]
+
+[ext_resource type="Script" path="res://scripts/main_menu.gd" id="1_main"]
+
+[node name="MainMenu" type="Control"]
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_main")
+
+[node name="CenterContainer" type="CenterContainer" parent="."]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+
+[node name="VBoxContainer" type="VBoxContainer" parent="CenterContainer"]
+layout_mode = 1
+theme_override_constants/separation = 16
+size_flags_horizontal = 4
+
+[node name="TitleLabel" type="Label" parent="CenterContainer/VBoxContainer"]
+layout_mode = 1
+text = "AGP Game"
+horizontal_alignment = 1
+theme_override_font_sizes/font_size = 72
+
+[node name="AuthPanel" type="PanelContainer" parent="CenterContainer/VBoxContainer"]
+layout_mode = 1
+visible = false
+
+[node name="MarginContainer" type="MarginContainer" parent="CenterContainer/VBoxContainer/AuthPanel"]
+layout_mode = 1
+theme_override_constants/margin_left = 24
+theme_override_constants/margin_top = 24
+theme_override_constants/margin_right = 24
+theme_override_constants/margin_bottom = 24
+
+[node name="AuthVBox" type="VBoxContainer" parent="CenterContainer/VBoxContainer/AuthPanel/MarginContainer"]
+layout_mode = 1
+theme_override_constants/separation = 8
+size_flags_horizontal = 3
+
+[node name="AuthModeLabel" type="Label" parent="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox"]
+layout_mode = 1
+text = "Login"
+horizontal_alignment = 1
+theme_override_font_sizes/font_size = 24
+
+[node name="UsernameEdit" type="LineEdit" parent="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox"]
+layout_mode = 1
+placeholder_text = "Username"
+size_flags_horizontal = 3
+
+[node name="PasswordEdit" type="LineEdit" parent="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox"]
+layout_mode = 1
+placeholder_text = "Password"
+size_flags_horizontal = 3
+echo_password = true
+
+[node name="EmailEdit" type="LineEdit" parent="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox"]
+layout_mode = 1
+visible = false
+placeholder_text = "Email"
+size_flags_horizontal = 3
+
+[node name="DOBEdit" type="LineEdit" parent="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox"]
+layout_mode = 1
+visible = false
+placeholder_text = "Date of Birth (YYYY-MM-DD)"
+size_flags_horizontal = 3
+
+[node name="ModeToggle" type="CheckButton" parent="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox"]
+layout_mode = 1
+text = "Register"
+
+[node name="AuthButton" type="Button" parent="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox"]
+layout_mode = 1
+text = "Login"
+size_flags_horizontal = 3
+
+[node name="AuthStatusLabel" type="Label" parent="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox"]
+layout_mode = 1
+text = ""
+horizontal_alignment = 1
+autowrap_mode = 2
+visible = false
+
+[node name="WelcomeLabel" type="Label" parent="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox"]
+layout_mode = 1
+visible = false
+text = ""
+horizontal_alignment = 1
+
+[node name="PlayButton" type="Button" parent="CenterContainer/VBoxContainer"]
+layout_mode = 1
+text = "Play"
+size_flags_horizontal = 4
+
+[node name="QuitButton" type="Button" parent="CenterContainer/VBoxContainer"]
+layout_mode = 1
+text = "Quit"
+size_flags_horizontal = 4
+
+[connection signal="pressed" from="CenterContainer/VBoxContainer/PlayButton" to="." method="_on_play_button_pressed"]
+[connection signal="pressed" from="CenterContainer/VBoxContainer/QuitButton" to="." method="_on_quit_button_pressed"]
+[connection signal="toggled" from="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/ModeToggle" to="." method="_on_mode_toggle_toggled"]
+[connection signal="pressed" from="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/AuthButton" to="." method="_on_auth_button_pressed"]
+[connection signal="text_submitted" from="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/UsernameEdit" to="." method="_on_auth_button_pressed"]
+[connection signal="text_submitted" from="CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/PasswordEdit" to="." method="_on_auth_button_pressed"]

scenes/world_list.tscn

@@ -0,0 +1,76 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://scripts/world_list.gd" id="1_wl"]
+
+[node name="WorldList" type="Control"]
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_wl")
+
+[node name="VBoxContainer" type="VBoxContainer" parent="."]
+layout_mode = 3
+theme_override_constants/separation = 8
+size_flags_horizontal = 4
+size_flags_vertical = 4
+
+[node name="HeaderHBox" type="HBoxContainer" parent="VBoxContainer"]
+layout_mode = 3
+size_flags_horizontal = 4
+theme_override_constants/separation = 16
+
+[node name="BackButton" type="Button" parent="VBoxContainer/HeaderHBox"]
+layout_mode = 3
+text = "< Back"
+size_flags_horizontal = 0
+
+[node name="TitleLabel" type="Label" parent="VBoxContainer/HeaderHBox"]
+layout_mode = 3
+text = "Browse Worlds"
+horizontal_alignment = 1
+size_flags_horizontal = 4
+theme_override_font_sizes/font_size = 28
+
+[node name="RefreshButton" type="Button" parent="VBoxContainer/HeaderHBox"]
+layout_mode = 3
+text = "Refresh"
+size_flags_horizontal = 0
+
+[node name="ScrollContainer" type="ScrollContainer" parent="VBoxContainer"]
+layout_mode = 3
+size_flags_horizontal = 4
+size_flags_vertical = 4
+horizontal_mode = 2
+vertical_mode = 2
+
+[node name="WorldList" type="VBoxContainer" parent="VBoxContainer/ScrollContainer"]
+layout_mode = 3
+size_flags_horizontal = 4
+size_flags_vertical = 4
+theme_override_constants/separation = 8
+
+[node name="LoadingLabel" type="Label" parent="VBoxContainer"]
+layout_mode = 3
+text = "Loading worlds..."
+visible = false
+horizontal_alignment = 1
+theme_override_font_sizes/font_size = 18
+
+[node name="ErrorLabel" type="Label" parent="VBoxContainer"]
+layout_mode = 3
+text = ""
+visible = false
+horizontal_alignment = 1
+theme_override_font_sizes/font_size = 18
+
+[node name="EmptyLabel" type="Label" parent="VBoxContainer"]
+layout_mode = 3
+text = ""
+visible = false
+horizontal_alignment = 1
+theme_override_font_sizes/font_size = 18
+
+[connection signal="pressed" from="VBoxContainer/HeaderHBox/BackButton" to="." method="_on_back_button_pressed"]
+[connection signal="pressed" from="VBoxContainer/HeaderHBox/RefreshButton" to="." method="_on_refresh_button_pressed"]

scripts/api_client.gd

@@ -0,0 +1,292 @@
+extends Node
+## Central HTTP client singleton (autoload name: "ApiClient").
+##
+## Every network call in the game flows through this class. Callers use the
+## high-level helpers ([method login], [method register], [method get_worlds],
+## [method health_check], [method get_me]) or the generic [method request]
+## primitive. All results conform to the result-dictionary contract below.
+##
+## [b]Result Dictionary Contract[/b]
+## Every public method returns (after `await`) a Dictionary with this shape:
+##
+##     {
+##         "ok":     bool,     # true for HTTP 2xx, false otherwise
+##         "status": int,      # HTTP status code (0 on network failure)
+##         "data":   Variant,  # parsed JSON body on success (null otherwise)
+##         "detail": String,   # human-readable message
+##     }
+##
+## Network failures (timeout / DNS / refused connection) return `status == 0`
+## with a `detail` describing the transport failure. Non-2xx responses return
+## the real HTTP status and the backend's `detail` field from the JSON error
+## body when present. No caller can crash on a failed request.
+##
+## [b]Token storage[/b]
+## JWTs are kept in memory. [method set_token] is the single seam for future
+## disk persistence (override it to save to `user://`).
+##
+## [b]Usage[/b]
+##     var result: Dictionary = await ApiClient.login("alice", "secret")
+##     if result.ok:
+##         print("Logged in!")
+##     else:
+##         print("Error: ", result.detail)
+
+# ---------------------------------------------------------------------------
+# Token storage
+# ---------------------------------------------------------------------------
+
+var _access_token: String = ""
+var _token_type: String = "Bearer"
+
+## Full Authorization header value, e.g. "Bearer eyJ...". Empty if no token.
+var bearer_token: String:
+	get:
+		return _token_type + " " + _access_token if _access_token != "" else ""
+
+
+## Whether an access token is currently stored.
+func has_token() -> bool:
+	return _access_token != ""
+
+
+## Set the access token (called after login / register / token refresh).
+## This is the persistence seam: override to also write to disk.
+func set_token(access_token: String, token_type: String = "Bearer") -> void:
+	_access_token = access_token
+	_token_type = token_type
+
+
+## Clear stored tokens.
+func clear_token() -> void:
+	_access_token = ""
+	_token_type = "Bearer"
+
+
+# ---------------------------------------------------------------------------
+# Configuration
+# ---------------------------------------------------------------------------
+
+var _base_url: String = "http://127.0.0.1:8000"
+
+## Request timeout in seconds. 0 disables the timeout.
+var timeout_seconds: float = 10.0
+
+
+func _ready() -> void:
+	# Environment variable override (e.g. for headless smoke tests against a
+	# backend on a non-default port). Falls back to the ProjectSetting, then
+	# to the documented default.
+	var env_url := OS.get_environment("AGP_API_BASE_URL")
+	if env_url != "":
+		_base_url = env_url.rstrip("/")
+	else:
+		_base_url = str(ProjectSettings.get_setting(
+			"application/agp/api_base_url",
+			"http://127.0.0.1:8000"
+		)).rstrip("/")
+
+
+# ---------------------------------------------------------------------------
+# Core request primitive
+# ---------------------------------------------------------------------------
+
+## Generic request primitive. Awaitable via `await`.
+##
+## Uses a dedicated HTTPRequest node per call so concurrent requests can never
+## cross-talk, and so the result maps 1:1 to the awaiting caller.
+##
+## @param method       HTTPClient.Method enum value (GET/POST/PUT/PATCH/DELETE).
+## @param path         URL path, e.g. "/api/health".
+## @param body         Request body string (JSON or form-encoded).
+## @param content_type "application/json" or "application/x-www-form-urlencoded".
+## @param require_auth If true, attach the stored bearer token when present.
+## @return Result dictionary conforming to the contract.
+func request(
+	method: HTTPClient.Method,
+	path: String,
+	body: String = "",
+	content_type: String = "application/json",
+	require_auth: bool = false
+) -> Dictionary:
+	var http := HTTPRequest.new()
+	http.timeout = timeout_seconds
+	http.max_redirects = 8
+	http.accept_gzip = true
+	add_child(http)
+
+	var headers := PackedStringArray()
+	headers.append("Accept: application/json")
+	if content_type != "":
+		headers.append("Content-Type: " + content_type)
+	if require_auth and has_token():
+		headers.append("Authorization: " + bearer_token)
+
+	var url := _base_url + path
+	var err := http.request(url, headers, method, body)
+	if err != OK:
+		http.queue_free()
+		return _make_result(false, 0, null, "Failed to start request: " + _error_string(err))
+
+	# request_completed emits (result, response_code, headers, body).
+	var args: Array = await http.request_completed
+	var result_code: int = args[0]
+	var response_code: int = args[1]
+	var response_body: PackedByteArray = args[3]
+	http.queue_free()
+
+	# Transport-level failure (timeout / DNS / refused / TLS, etc.).
+	if result_code != HTTPRequest.RESULT_SUCCESS:
+		return _make_result(false, 0, null, _transport_error_detail(result_code))
+
+	# Server accepted the connection but returned no HTTP status line.
+	if response_code == 0:
+		return _make_result(false, 0, null, "No response received from server.")
+
+	var json_string := response_body.get_string_from_utf8()
+	var ok := response_code >= 200 and response_code < 300
+
+	if ok:
+		var data: Variant = _parse_json(json_string)
+		return _make_result(true, response_code, data, "OK")
+
+	# Non-2xx: surface the backend's "detail" message when available.
+	var detail := "HTTP error %d" % response_code
+	var parsed: Variant = _parse_json(json_string)
+	if parsed is Dictionary and (parsed as Dictionary).has("detail"):
+		detail = str((parsed as Dictionary)["detail"])
+	return _make_result(false, response_code, null, detail)
+
+
+# ---------------------------------------------------------------------------
+# High-level helpers
+# ---------------------------------------------------------------------------
+
+## Log in with username/password (OAuth2PasswordRequestForm).
+## On success stores the returned access token.
+func login(username: String, password: String) -> Dictionary:
+	var form := "username=" + username.uri_encode() + "&password=" + password.uri_encode()
+	var result := await request(
+		HTTPClient.METHOD_POST,
+		"/api/auth/login",
+		form,
+		"application/x-www-form-urlencoded",
+		false
+	)
+	_store_token_from_result(result)
+	return result
+
+
+## Register a new user. On success stores the returned access token.
+## @param date_of_birth ISO date string "YYYY-MM-DD".
+func register(
+	username: String,
+	email: String,
+	password: String,
+	date_of_birth: String
+) -> Dictionary:
+	var payload := {
+		"username": username,
+		"email": email,
+		"password": password,
+		"date_of_birth": date_of_birth,
+	}
+	var result := await request(
+		HTTPClient.METHOD_POST,
+		"/api/auth/register",
+		JSON.stringify(payload),
+		"application/json",
+		false
+	)
+	_store_token_from_result(result)
+	return result
+
+
+## List worlds visible to the current user (requires auth).
+## @param visibility Optional filter: "public", "private", "friends_only".
+func get_worlds(skip: int = 0, limit: int = 50, visibility: String = "") -> Dictionary:
+	var path := "/api/worlds/?skip=%d&limit=%d" % [skip, limit]
+	if visibility != "":
+		path += "&visibility=" + visibility.uri_encode()
+	return await request(HTTPClient.METHOD_GET, path, "", "application/json", true)
+
+
+## Ping the backend health endpoint (no auth).
+func health_check() -> Dictionary:
+	return await request(HTTPClient.METHOD_GET, "/api/health", "", "application/json", false)
+
+
+## Fetch the current user's profile from the stored JWT (requires auth).
+func get_me() -> Dictionary:
+	return await request(HTTPClient.METHOD_GET, "/api/users/me", "", "application/json", true)
+
+
+# ---------------------------------------------------------------------------
+# Internals
+# ---------------------------------------------------------------------------
+
+func _store_token_from_result(result: Dictionary) -> void:
+	if result.ok and result.data is Dictionary:
+		var token: String = str((result.data as Dictionary).get("access_token", ""))
+		if token != "":
+			set_token(token)
+
+
+func _parse_json(text: String) -> Variant:
+	if text == "":
+		return null
+	var parsed: Variant = JSON.parse_string(text)
+	if parsed == null:
+		# null is ambiguous (valid JSON "null" vs parse failure). Fall back to
+		# the raw string so callers never lose the body entirely.
+		return text if text != "null" else null
+	return parsed
+
+
+func _make_result(ok: bool, status: int, data: Variant, detail: String) -> Dictionary:
+	return {
+		"ok": ok,
+		"status": status,
+		"data": data,
+		"detail": detail,
+	}
+
+
+func _transport_error_detail(result_code: int) -> String:
+	match result_code:
+		HTTPRequest.RESULT_CANT_CONNECT:
+			return "Could not connect to server. Is it running?"
+		HTTPRequest.RESULT_CANT_RESOLVE:
+			return "Could not resolve server hostname."
+		HTTPRequest.RESULT_CONNECTION_ERROR:
+			return "Connection error."
+		HTTPRequest.RESULT_TLS_HANDSHAKE_ERROR:
+			return "TLS handshake failed."
+		HTTPRequest.RESULT_NO_RESPONSE:
+			return "No response from server."
+		HTTPRequest.RESULT_BODY_SIZE_LIMIT_EXCEEDED:
+			return "Response body too large."
+		HTTPRequest.RESULT_BODY_DECOMPRESS_FAILED:
+			return "Failed to decompress response body."
+		HTTPRequest.RESULT_REQUEST_FAILED:
+			return "Request failed."
+		HTTPRequest.RESULT_TIMEOUT:
+			return "Request timed out."
+		_:
+			return "Network error (code %d)." % result_code
+
+
+func _error_string(err_code: int) -> String:
+	match err_code:
+		OK:
+			return "OK"
+		ERR_UNCONFIGURED:
+			return "HTTPRequest not configured (not in tree)."
+		ERR_BUSY:
+			return "HTTPRequest is busy with a previous request."
+		ERR_INVALID_PARAMETER:
+			return "Invalid URL format."
+		ERR_CANT_CONNECT:
+			return "Cannot connect to host."
+		_:
+			return "Unknown error (%d)." % err_code

scripts/api_client.gd.uid

@@ -0,0 +1 @@
+uid://cjd0uhll7iylj

scripts/build.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+# Headless CI export for Linux and Windows.
+#
+# Requires:
+#   - Godot 4.6.2 (the exact version this project + export_presets.cfg were
+#     built against; a different Godot minor version's export templates are
+#     not guaranteed compatible)
+#   - The matching export templates installed at
+#     ~/.local/share/godot/export_templates/4.6.2.stable/
+#     (download: https://godotengine.org/download/archive/4.6.2-stable/,
+#     "Export templates" -- NOT the same as the editor download)
+#   - godot on PATH (or set GODOT_BIN below)
+#
+# Usage: scripts/build.sh
+# Output: export/linux/agp-game.x86_64, export/windows/agp-game.exe
+
+set -euo pipefail
+cd "$(dirname "$0")/.."
+
+GODOT_BIN="${GODOT_BIN:-godot}"
+if ! command -v "$GODOT_BIN" >/dev/null 2>&1; then
+    if [ -x "$HOME/godot/godot" ]; then
+        GODOT_BIN="$HOME/godot/godot"
+    else
+        echo "godot binary not found (checked PATH and ~/godot/godot)." >&2
+        exit 1
+    fi
+fi
+
+echo "Godot version: $("$GODOT_BIN" --version)"
+
+mkdir -p export/linux export/windows
+
+echo "=== Exporting Linux/X11 ==="
+"$GODOT_BIN" --headless --path . --export-release "Linux" export/linux/agp-game.x86_64
+
+echo "=== Exporting Windows Desktop ==="
+"$GODOT_BIN" --headless --path . --export-release "Windows Desktop" export/windows/agp-game.exe
+
+echo ""
+echo "Build artifacts:"
+ls -la export/linux export/windows

scripts/main_menu.gd

@@ -0,0 +1,212 @@
+extends Control
+## Main menu with login/register UI wired to the backend auth API.
+##
+## The AuthPanel is hidden by default. When the user clicks "Login" or "Register"
+## (the existing Play/Quit buttons), the auth panel slides in. The ModeToggle
+## switches between Login and Register modes, showing/hiding the email and DOB
+## fields accordingly.
+##
+## On successful auth the token is stored via ApiClient, the welcome label
+## shows the username, and the Play button becomes enabled.
+
+
+# ── UI references ────────────────────────────────────────────────────────────
+
+var _auth_panel: PanelContainer
+var _auth_mode_label: Label
+var _username_edit: LineEdit
+var _password_edit: LineEdit
+var _email_edit: LineEdit
+var _dob_edit: LineEdit
+var _mode_toggle: CheckButton
+var _auth_button: Button
+var _status_label: Label
+var _welcome_label: Label
+var _play_button: Button
+var _quit_button: Button
+
+var _is_register_mode: bool = false
+var _is_authenticating: bool = false
+
+
+# ── Lifecycle ────────────────────────────────────────────────────────────────
+
+func _ready() -> void:
+	# Cache node references.
+	_auth_panel = $CenterContainer/VBoxContainer/AuthPanel
+	_auth_mode_label = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/AuthModeLabel
+	_username_edit = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/UsernameEdit
+	_password_edit = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/PasswordEdit
+	_email_edit = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/EmailEdit
+	_dob_edit = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/DOBEdit
+	_mode_toggle = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/ModeToggle
+	_auth_button = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/AuthButton
+	_status_label = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/AuthStatusLabel
+	_welcome_label = $CenterContainer/VBoxContainer/AuthPanel/MarginContainer/AuthVBox/WelcomeLabel
+	_play_button = $CenterContainer/VBoxContainer/PlayButton
+	_quit_button = $CenterContainer/VBoxContainer/QuitButton
+
+	# Initial state.
+	_auth_panel.visible = false
+	_status_label.visible = false
+	_welcome_label.visible = false
+	_email_edit.visible = false
+	_dob_edit.visible = false
+	_play_button.disabled = true  # Gate play behind successful auth.
+	_update_auth_mode_ui()
+
+
+# ── Play / Quit ──────────────────────────────────────────────────────────────
+
+func _on_play_button_pressed() -> void:
+	if _play_button.disabled:
+		return
+	# Browse worlds is the first real screen past login -- actual gameplay
+	# (joining a world) doesn't exist yet, browsing does.
+	get_tree().change_scene_to_file("res://scenes/world_list.tscn")
+
+
+func _on_quit_button_pressed() -> void:
+	get_tree().quit()
+
+
+# ── Auth panel toggle ────────────────────────────────────────────────────────
+
+func _on_login_button_pressed() -> void:
+	"""Show the auth panel (called from a future Login button on the main menu)."""
+	_auth_panel.visible = true
+	_auth_panel.grab_focus()
+
+
+func _on_register_button_pressed() -> void:
+	"""Show the auth panel in register mode."""
+	_auth_panel.visible = true
+	_is_register_mode = true
+	_mode_toggle.button_pressed = true
+	_update_auth_mode_ui()
+	_clear_status()
+
+
+# ── Mode toggle (Login / Register) ───────────────────────────────────────────
+
+func _on_mode_toggle_toggled(button_pressed: bool) -> void:
+	_is_register_mode = button_pressed
+	_update_auth_mode_ui()
+	_clear_status()
+
+
+func _update_auth_mode_ui() -> void:
+	"""Update labels and field visibility based on login vs register mode."""
+	if _is_register_mode:
+		_auth_mode_label.text = "Register"
+		_auth_button.text = "Register"
+		_email_edit.visible = true
+		_dob_edit.visible = true
+	else:
+		_auth_mode_label.text = "Login"
+		_auth_button.text = "Login"
+		_email_edit.visible = false
+		_dob_edit.visible = false
+
+
+# ── Auth submission ──────────────────────────────────────────────────────────
+
+func _on_auth_button_pressed() -> void:
+	"""Handle login or register button press."""
+	if _is_authenticating:
+		return
+
+	# Validate inputs.
+	var username := _username_edit.text.strip_edges()
+	var password := _password_edit.text
+
+	if username == "":
+		_show_status("Username is required.")
+		return
+	if password == "":
+		_show_status("Password is required.")
+		return
+
+	if _is_register_mode:
+		var email := _email_edit.text.strip_edges()
+		var dob := _dob_edit.text.strip_edges()
+
+		if email == "":
+			_show_status("Email is required.")
+			return
+		if dob == "":
+			_show_status("Date of birth is required.")
+			return
+		# Basic YYYY-MM-DD format check.
+		if not _is_valid_date(dob):
+			_show_status("Date of birth must be in YYYY-MM-DD format.")
+			return
+
+		_auth_button.disabled = true
+		_auth_button.text = "Registering..."
+		_is_authenticating = true
+		_clear_status()
+
+		var result := await ApiClient.register(username, email, password, dob)
+		_on_auth_complete(result)
+	else:
+		_auth_button.disabled = true
+		_auth_button.text = "Logging in..."
+		_is_authenticating = true
+		_clear_status()
+
+		var result := await ApiClient.login(username, password)
+		_on_auth_complete(result)
+
+
+func _on_auth_complete(result: Dictionary) -> void:
+	"""Handle the result of a login or register call."""
+	_auth_button.disabled = false
+	_auth_button.text = "Register" if _is_register_mode else "Login"
+	_is_authenticating = false
+
+	if result.ok:
+		# Success — show welcome, enable Play.
+		_welcome_label.text = "Welcome, %s!" % _username_edit.text.strip_edges()
+		_welcome_label.visible = true
+		_status_label.visible = false
+		_play_button.disabled = false
+		print("Auth successful. Token stored.")
+	else:
+		# Failure — show backend error detail.
+		_show_status(result.detail)
+
+
+# ── Status helpers ───────────────────────────────────────────────────────────
+
+func _show_status(message: String) -> void:
+	_status_label.text = message
+	_status_label.visible = true
+
+
+func _clear_status() -> void:
+	_status_label.text = ""
+	_status_label.visible = false
+
+
+# ── Validation ───────────────────────────────────────────────────────────────
+
+func _is_valid_date(date_str: String) -> bool:
+	"""Check if a string looks like a valid YYYY-MM-DD date."""
+	if date_str.length() != 10:
+		return false
+	var parts := date_str.split("-")
+	if parts.size() != 3:
+		return false
+	var year := parts[0].to_int()
+	var month := parts[1].to_int()
+	var day := parts[2].to_int()
+	if month < 1 or month > 12:
+		return false
+	if day < 1 or day > 31:
+		return false
+	# Rough month-day validation.
+	var days_in_month := [0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
+	if day > days_in_month[month]:
+		return false
+	return true

scripts/main_menu.gd.uid

@@ -0,0 +1 @@
+uid://bgnc3iamfgf6k

scripts/run_checkpoint_tests.py

@@ -0,0 +1,170 @@
+#!/usr/bin/env python3
+"""Run the full automated test inventory for a Package Checkpoint review.
+
+See docs/testing/test_inventory.md for what each suite actually covers (and
+doesn't) -- keep that doc in sync as tests are added, this script just runs
+whatever's there.
+
+Usage:
+    python scripts/run_checkpoint_tests.py [--keep-postgres] [--postgres-port PORT]
+
+Exits 0 if everything that ran passed, 1 otherwise. Suites with nothing to
+run (e.g. no scripts/smoke_test_*.gd yet, or no Godot binary found) are
+reported as SKIPPED, not counted as a failure.
+"""
+import argparse
+import glob
+import os
+import shutil
+import subprocess
+import sys
+import time
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+BACKEND = ROOT / "backend"
+
+
+def run(cmd, cwd=None, env=None, capture=False):
+    print(f"$ {' '.join(cmd)}" + (f"  (cwd={cwd})" if cwd else ""))
+    return subprocess.run(cmd, cwd=cwd, env=env, capture_output=capture, text=True)
+
+
+def find_godot():
+    for candidate in ("godot", str(Path.home() / "godot" / "godot")):
+        if shutil.which(candidate) or Path(candidate).is_file():
+            return candidate
+    return None
+
+
+def wait_for_http(url: str, timeout_s: int = 20) -> bool:
+    import urllib.request
+    import urllib.error
+
+    deadline = time.time() + timeout_s
+    while time.time() < deadline:
+        try:
+            with urllib.request.urlopen(url, timeout=2) as resp:
+                if resp.status == 200:
+                    return True
+        except (urllib.error.URLError, ConnectionError, OSError):
+            pass
+        time.sleep(1)
+    return False
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
+    parser.add_argument("--keep-postgres", action="store_true",
+                         help="Don't tear down the checkpoint Postgres container afterward")
+    parser.add_argument("--postgres-port", default=os.environ.get("CHECKPOINT_POSTGRES_PORT", "5432"),
+                         help="Host port for the checkpoint's own Postgres container (default 5432 -- "
+                              "override if that's already in use on this machine)")
+    parser.add_argument("--backend-port", default=os.environ.get("CHECKPOINT_BACKEND_PORT", "18080"),
+                         help="Port to run the backend server on for the Godot smoke tests")
+    args = parser.parse_args()
+
+    results = {}
+
+    # --- Backend: bring up Postgres ---
+    compose_env = os.environ.copy()
+    compose_env["COMPOSE_PROJECT_NAME"] = "agp-checkpoint"
+    compose_env["POSTGRES_HOST_PORT"] = args.postgres_port
+    compose_env["POSTGRES_PORT"] = args.postgres_port  # some branches use this name instead, see tools/definitions.py
+    print("=== Backend: bringing up Postgres ===")
+    run(["docker", "compose", "up", "-d", "postgres"], cwd=BACKEND, env=compose_env)
+
+    print("Waiting for Postgres to be ready...")
+    pg_ready = False
+    for _ in range(20):
+        r = run(["docker", "compose", "exec", "-T", "postgres", "pg_isready", "-U", "agp_user", "-d", "agp_db"],
+                cwd=BACKEND, env=compose_env, capture=True)
+        if r.returncode == 0:
+            pg_ready = True
+            break
+        time.sleep(1)
+    if not pg_ready:
+        print("Postgres never became ready -- aborting.")
+        sys.exit(1)
+
+    db_url = f"postgresql+asyncpg://agp_user:agp_password@localhost:{args.postgres_port}/agp_db"
+    backend_env = os.environ.copy()
+    backend_env["DATABASE_URL"] = db_url
+
+    print("\n=== Backend: alembic upgrade head ===")
+    r = run([sys.executable, "-m", "alembic", "upgrade", "head"], cwd=BACKEND, env=backend_env)
+    results["migrations (fresh DB)"] = r.returncode == 0
+
+    print("\n=== Backend: pytest ===")
+    r = run([sys.executable, "-m", "pytest", "-v"], cwd=BACKEND, env=backend_env)
+    results["backend pytest"] = r.returncode == 0
+
+    # --- Godot: headless smoke tests (need a live backend server) ---
+    godot_bin = find_godot()
+    smoke_tests = sorted(glob.glob(str(ROOT / "scripts" / "smoke_test_*.gd")))
+
+    if not godot_bin:
+        print("\n=== Godot: binary not found (checked PATH and ~/godot/godot), skipping smoke tests ===")
+        results["godot smoke tests"] = None
+    elif not smoke_tests:
+        print("\n=== Godot: no scripts/smoke_test_*.gd found yet, nothing to run ===")
+        results["godot smoke tests"] = None
+    else:
+        print(f"\n=== Backend: starting server on :{args.backend_port} for Godot smoke tests ===")
+        server_proc = subprocess.Popen(
+            [sys.executable, "-m", "uvicorn", "app.main:app", "--host", "127.0.0.1", "--port", args.backend_port],
+            cwd=BACKEND, env=backend_env,
+            stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL,
+        )
+        try:
+            base_url = f"http://127.0.0.1:{args.backend_port}"
+            if not wait_for_http(f"{base_url}/api/health"):
+                print("Backend server never became healthy -- skipping Godot smoke tests.")
+                results["godot smoke tests"] = False
+            else:
+                godot_env = os.environ.copy()
+                godot_env["AGP_API_BASE_URL"] = base_url
+
+                print("=== Godot: import pass (builds the class cache) ===")
+                run([godot_bin, "--headless", "--path", str(ROOT), "--import"], env=godot_env)
+                run([godot_bin, "--headless", "--path", str(ROOT), "--quit"], env=godot_env)
+
+                godot_ok = True
+                for test in smoke_tests:
+                    rel = os.path.relpath(test, ROOT)
+                    print(f"\n--- {rel} ---")
+                    r = run([godot_bin, "--headless", "--path", str(ROOT), "--script", f"res://{rel}"], env=godot_env)
+                    if r.returncode != 0:
+                        godot_ok = False
+                results["godot smoke tests"] = godot_ok
+        finally:
+            server_proc.terminate()
+            try:
+                server_proc.wait(timeout=10)
+            except subprocess.TimeoutExpired:
+                server_proc.kill()
+
+    if not args.keep_postgres:
+        print("\n=== Backend: tearing down checkpoint Postgres ===")
+        run(["docker", "compose", "down", "-v", "postgres"], cwd=BACKEND, env=compose_env)
+
+    # --- Summary ---
+    print("\n" + "=" * 50)
+    print("SUMMARY")
+    print("=" * 50)
+    overall_ok = True
+    for name, ok in results.items():
+        if ok is None:
+            print(f"  {name}: SKIPPED")
+        elif ok:
+            print(f"  {name}: PASS")
+        else:
+            print(f"  {name}: FAIL")
+            overall_ok = False
+
+    print("\nSee docs/testing/test_inventory.md for what each suite actually covers (and doesn't).")
+    sys.exit(0 if overall_ok else 1)
+
+
+if __name__ == "__main__":
+    main()

scripts/smoke_test_api.gd

@@ -0,0 +1,46 @@
+extends SceneTree
+## Headless smoke test for the ApiClient autoload.
+##
+## Run with:
+##     godot --headless --path . --script res://scripts/smoke_test_api.gd
+##
+## Requires the backend to be running (default base URL
+## `application/agp/api_base_url` -> http://127.0.0.1:8000).
+##
+## Calls the real autoload's `health_check()` (which exercises the generic
+## `request()` primitive) and exits 0 on a `status == "ok"` response, 1
+## otherwise. This script is intentionally NOT wired into any game scene.
+
+
+func _initialize() -> void:
+	_run()
+
+
+func _run() -> void:
+	# _initialize() fires before the SceneTree has processed its first frame,
+	# so a freshly add_child()'d HTTPRequest node isn't reliably considered
+	# "inside tree" yet (request_raw fails with !is_inside_tree()). One frame
+	# of delay is enough; this only matters for --script mode, not a real
+	# running game.
+	await process_frame
+
+	# Godot's --script/SceneTree runner doesn't resolve autoload singletons
+	# as bare global identifiers at compile time (the node exists at
+	# runtime -- root.has_node("ApiClient") is true -- but referencing it as
+	# a plain identifier fails with "Identifier not found: ApiClient" during
+	# script compilation). get_node sidesteps compile-time resolution
+	# entirely. This only affects --script mode; a real game scene resolves
+	# the bare autoload name normally.
+	var api_client := root.get_node("ApiClient")
+	print("SMOKE: calling ApiClient.health_check() ...")
+	var result: Dictionary = await api_client.health_check()
+	print("SMOKE: result = ", result)
+
+	if result.ok \
+			and result.data is Dictionary \
+			and str((result.data as Dictionary).get("status", "")) == "ok":
+		print("SMOKE RESULT: PASS (status=ok)")
+		quit(0)
+	else:
+		printerr("SMOKE RESULT: FAIL")
+		quit(1)

scripts/smoke_test_auth.gd

@@ -0,0 +1,133 @@
+extends SceneTree
+## Headless smoke test for the AuthPanel login/register flow.
+##
+## Run with:
+##     godot --headless --path . --script res://scripts/smoke_test_auth.gd
+##
+## Requires the backend to be running (default base URL
+## `application/agp/api_base_url` -> http://127.0.0.1:8000).
+##
+## Tests:
+##   1. Register a unique user → 201 + token stored.
+##   2. Register the same user again → 409 "Username already registered".
+##   3. Register an under-18 user → 400 "Must be 18 or older".
+##   4. Login with correct credentials → 200 + token stored.
+##   5. Login with wrong password → 401 "Incorrect username or password".
+##   6. Login with non-existent user → 401 "Incorrect username or password".
+##
+## Exits 0 on full pass, 1 on any failure.
+
+const API_BASE := "http://127.0.0.1:8000"
+const TEST_USERNAME := "smoke_test_user_%d"
+const TEST_EMAIL := "smoke_%d@test.example.com"
+const TEST_PASSWORD := "SmokeTest123!"
+const TEST_DOB_ADULT := "2000-01-01"
+const TEST_DOB_CHILD := "2020-01-01"  # ~5 years old
+
+
+func _initialize() -> void:
+	_run()
+
+
+func _run() -> void:
+	# Wait for autoloads to be ready.
+	await process_frame
+
+	var api := root.get_node("ApiClient") as ApiClient
+	assert(api != null, "ApiClient autoload not found")
+
+	var passed: int = 0
+	var failed: int = 0
+
+	# --- Test 1: Register a unique user ---
+	var unique_id := Time.get_ticks_msec()
+	var username := "smoke_%d" % unique_id
+	var email := "smoke_%d@test.example.com" % unique_id
+
+	print("\n=== Test 1: Register unique user ===")
+	var result := await api.register(username, email, TEST_PASSWORD, TEST_DOB_ADULT)
+	if _check("register returns ok", result.ok) \
+			and _check("register status is 201", result.status == 201) \
+			and _check("register stores token", api.has_token()):
+		passed += 1
+	else:
+		failed += 1
+		print("  detail: ", result.detail)
+
+	# --- Test 2: Register same user again (duplicate) ---
+	print("\n=== Test 2: Duplicate username ===")
+	result = await api.register(username, email, TEST_PASSWORD, TEST_DOB_ADULT)
+	if _check("duplicate register not ok", not result.ok) \
+			and _check("duplicate status is 409", result.status == 409) \
+			and _check("duplicate detail mentions username",
+					"username" in result.detail.to_lower()):
+		passed += 1
+	else:
+		failed += 1
+		print("  detail: ", result.detail)
+
+	# --- Test 3: Register under-18 user ---
+	print("\n=== Test 3: Under-18 registration ===")
+	var child_username := "child_%d" % unique_id
+	var child_email := "child_%d@test.example.com" % unique_id
+	result = await api.register(child_username, child_email, TEST_PASSWORD, TEST_DOB_CHILD)
+	if _check("under-18 register not ok", not result.ok) \
+			and _check("under-18 status is 400", result.status == 400) \
+			and _check("under-18 detail mentions age",
+					"18" in result.detail):
+		passed += 1
+	else:
+		failed += 1
+		print("  detail: ", result.detail)
+
+	# --- Test 4: Login with correct credentials ---
+	print("\n=== Test 4: Correct login ===")
+	result = await api.login(username, TEST_PASSWORD)
+	if _check("login returns ok", result.ok) \
+			and _check("login status is 200", result.status == 200) \
+			and _check("login stores token", api.has_token()):
+		passed += 1
+	else:
+		failed += 1
+		print("  detail: ", result.detail)
+
+	# --- Test 5: Login with wrong password ---
+	print("\n=== Test 5: Wrong password ===")
+	result = await api.login(username, "WrongPassword!")
+	if _check("wrong pwd login not ok", not result.ok) \
+			and _check("wrong pwd status is 401", result.status == 401) \
+			and _check("wrong pwd detail",
+					"Incorrect" in result.detail or "incorrect" in result.detail):
+		passed += 1
+	else:
+		failed += 1
+		print("  detail: ", result.detail)
+
+	# --- Test 6: Login with non-existent user ---
+	print("\n=== Test 6: Non-existent user ===")
+	result = await api.login("nonexistent_user_xyz", TEST_PASSWORD)
+	if _check("missing user login not ok", not result.ok) \
+			and _check("missing user status is 401", result.status == 401) \
+			and _check("missing user detail",
+					"Incorrect" in result.detail or "incorrect" in result.detail):
+		passed += 1
+	else:
+		failed += 1
+		print("  detail: ", result.detail)
+
+	# --- Summary ---
+	print("\n=== SMOKE RESULT: %d/%d passed ===" % [passed, passed + failed])
+	if failed > 0:
+		quit(1)
+	else:
+		print("SMOKE RESULT: ALL PASS")
+		quit(0)
+
+
+func _check(description: String, condition: bool) -> bool:
+	if condition:
+		print("  PASS: ", description)
+		return true
+	else:
+		printerr("  FAIL: ", description)
+		return false

scripts/smoke_test_e2e.gd

@@ -0,0 +1,148 @@
+extends SceneTree
+## End-to-end headless smoke test: register -> login -> fetch worlds list.
+##
+## Run with:
+##     godot --headless --path . --script res://scripts/smoke_test_e2e.gd
+##
+## Requires the backend to be running (default base URL
+## `application/agp/api_base_url` -> http://127.0.0.1:8000, overridable via
+## the AGP_API_BASE_URL environment variable).
+##
+## Steps:
+##   1. Health check  GET  /api/health          -> 200, {"status": "ok"}
+##   2. Register      POST /api/auth/register   -> 201, access_token present
+##   3. Login         POST /api/auth/login      -> 200, access_token present
+##   4. Worlds list   GET  /api/worlds          -> 200, JSON array
+##
+## Exits 0 if all steps pass, 1 otherwise. If the backend is unreachable the
+## health check fails with a clear message and the script exits 1 immediately.
+
+# Fixed credentials from the task spec. The username gets a unique numeric
+# suffix so the test stays re-runnable (a second run would otherwise hit
+# "Username already registered" on step 2).
+const TEST_USERNAME_BASE := "smoke_test_user"
+const TEST_EMAIL := "smoke@test.com"
+const TEST_PASSWORD := "TestPass123"
+const TEST_DOB := "2000-01-01"
+
+
+func _initialize() -> void:
+	_run()
+
+
+func _run() -> void:
+	# _initialize() fires before the first frame; wait one frame so freshly
+	# created HTTPRequest nodes are reliably inside the tree.
+	await process_frame
+
+	# In --script mode the autoload is reachable via get_node(), not as a
+	# bare identifier (bare identifiers fail to resolve at compile time here).
+	var api := root.get_node("ApiClient")
+	assert(api != null, "ApiClient autoload not found in the scene tree")
+
+	var unique_id := int(Time.get_unix_time_from_system() * 1000)
+	var username := "%s_%d" % [TEST_USERNAME_BASE, unique_id]
+	var email := "smoke_%d@test.com" % unique_id
+
+	var results := {}
+
+	# --- Step 1: Health check -------------------------------------------------
+	print("\n=== Step 1: Health check (GET /api/health) ===")
+	var health: Dictionary = await api.health_check()
+	var health_ok: bool = (
+		health.ok
+		and health.status == 200
+		and health.data is Dictionary
+		and str((health.data as Dictionary).get("status", "")) == "ok"
+	)
+	_record(results, "health", health_ok, "status=%d data=%s" % [
+		health.status, health.data
+	])
+
+	if not health.ok or health.status == 0:
+		printerr("\nERROR: Backend is not reachable at the configured base URL.")
+		printerr("       detail: %s" % health.detail)
+		printerr("       Start the backend first (see backend/README), then re-run:")
+		printerr("       godot --headless --path . --script res://scripts/smoke_test_e2e.gd")
+		_summarize(results)
+		quit(1)
+		return
+
+	# --- Step 2: Register -----------------------------------------------------
+	print("\n=== Step 2: Register (POST /api/auth/register) ===")
+	var reg: Dictionary = await api.register(username, email, TEST_PASSWORD, TEST_DOB)
+	var reg_token := _extract_token(reg)
+	var reg_ok: bool = (
+		reg.ok
+		and reg.status == 201
+		and reg_token != ""
+	)
+	_record(results, "register", reg_ok, "status=%d token=%s detail=%s" % [
+		reg.status, "yes" if reg_token != "" else "no", reg.detail
+	])
+
+	# --- Step 3: Login --------------------------------------------------------
+	print("\n=== Step 3: Login (POST /api/auth/login) ===")
+	var login: Dictionary = await api.login(username, TEST_PASSWORD)
+	var login_token := _extract_token(login)
+	var login_ok: bool = (
+		login.ok
+		and login.status == 200
+		and login_token != ""
+	)
+	_record(results, "login", login_ok, "status=%d token=%s detail=%s" % [
+		login.status, "yes" if login_token != "" else "no", login.detail
+	])
+
+	# --- Step 4: Worlds list ---------------------------------------------------
+	print("\n=== Step 4: Worlds list (GET /api/worlds) ===")
+	# login/register already stored the token; make the auth header explicit by
+	# re-applying the extracted token so step 4 is independent of storage order.
+	if login_token != "":
+		api.set_token(login_token)
+	var worlds: Dictionary = await api.get_worlds()
+	var worlds_ok: bool = (
+		worlds.ok
+		and worlds.status == 200
+		and worlds.data is Array
+	)
+	_record(results, "worlds", worlds_ok, "status=%d is_array=%s count=%d detail=%s" % [
+		worlds.status,
+		"yes" if (worlds.data is Array) else "no",
+		(worlds.data as Array).size() if (worlds.data is Array) else -1,
+		worlds.detail,
+	])
+
+	# --- Summary ---------------------------------------------------------------
+	_summarize(results)
+
+
+func _extract_token(result: Dictionary) -> String:
+	if result.ok and result.data is Dictionary:
+		return str((result.data as Dictionary).get("access_token", ""))
+	return ""
+
+
+func _record(results: Dictionary, name: String, ok: bool, detail: String) -> void:
+	results[name] = {"ok": ok, "detail": detail}
+	if ok:
+		print("  PASS: %s" % detail)
+	else:
+		printerr("  FAIL: %s" % detail)
+
+
+func _summarize(results: Dictionary) -> void:
+	var all_pass := true
+	print("\n=== Smoke test summary ===")
+	for step in ["health", "register", "login", "worlds"]:
+		var entry: Dictionary = results.get(step, {"ok": false, "detail": "not run"})
+		if not entry["ok"]:
+			all_pass = false
+		print("  %-8s : %s" % [step, "PASS" if entry["ok"] else "FAIL"])
+
+	if all_pass:
+		print("SMOKE RESULT: ALL PASS (4/4)")
+		quit(0)
+	else:
+		printerr("SMOKE RESULT: FAIL")
+		quit(1)

scripts/smoke_test_world_list.gd

@@ -0,0 +1,122 @@
+extends SceneTree
+## Headless smoke test for the world list screen.
+##
+## Run with:
+##     godot --headless --path . --script res://scripts/smoke_test_world_list.gd
+##
+## Requires the backend to be running (default base URL
+## `application/agp/api_base_url` -> http://127.0.0.1:8000, override with
+## AGP_API_BASE_URL).
+##
+## Unlike a pure API-level test, this actually instantiates scenes/
+## world_list.tscn as a real scene and adds it to the tree -- catches
+## @onready node-path bugs (a node reference pointing at the wrong path
+## errors right here, not just "looks right" from reading the script) that
+## an API-only test would miss entirely.
+##
+## Tests:
+##   1. Register + log in a fresh user (so get_worlds() has a valid token).
+##   2. Instantiate world_list.tscn, add to tree -- @onready resolution
+##      must not error.
+##   3. Wait for _refresh_worlds()'s awaited request to complete.
+##   4. Confirm the screen reached a real end state (world cards, or the
+##      empty-list message -- either is fine, a crash/stuck-loading isn't).
+##
+## Exits 0 on full pass, 1 on any failure.
+
+const WORLD_LIST_SCENE := "res://scenes/world_list.tscn"
+
+
+func _initialize() -> void:
+	_run()
+
+
+func _run() -> void:
+	await process_frame
+
+	var api := root.get_node("ApiClient")
+	assert(api != null, "ApiClient autoload not found")
+
+	var passed: int = 0
+	var failed: int = 0
+
+	# --- Setup: register + log in so the world list has a valid token ---
+	print("\n=== Setup: register + login ===")
+	randomize()
+	var unique_id: int = int(Time.get_unix_time_from_system() * 1000) + randi() % 100000
+	var username := "worldlist_smoke_%d" % unique_id
+	var email := "worldlist_smoke_%d@test.example.com" % unique_id
+	var reg_result: Dictionary = await api.register(username, email, "SmokeTest123!", "2000-01-01")
+	if not _check("setup: register succeeded", reg_result.ok):
+		print("  detail: ", reg_result.detail)
+		quit(1)
+		return
+
+	# --- Test 1: Instantiate the real scene ---
+	print("\n=== Test 1: Instantiate world_list.tscn ===")
+	var packed_scene: PackedScene = load(WORLD_LIST_SCENE)
+	if not _check("scene loads", packed_scene != null):
+		quit(1)
+		return
+
+	var instance: Control = packed_scene.instantiate()
+	if not _check("scene instantiates", instance != null):
+		quit(1)
+		return
+
+	root.add_child(instance)
+	# One frame for _ready() (and its @onready resolution) to run. A wrong
+	# node path in an @onready var errors during this, not silently.
+	await process_frame
+
+	if _check("scene added to tree without error", is_instance_valid(instance)):
+		passed += 1
+	else:
+		failed += 1
+
+	# --- Test 2: Wait for the world fetch to resolve, check a real end state ---
+	print("\n=== Test 2: World fetch reaches a real end state ===")
+	# _refresh_worlds() runs from _ready(); give its awaited HTTP call time
+	# to complete rather than a fixed sleep -- poll for either end state.
+	var world_list_node: VBoxContainer = instance.get_node("VBoxContainer/ScrollContainer/WorldList")
+	var empty_label: Label = instance.get_node("VBoxContainer/EmptyLabel")
+	var error_label: Label = instance.get_node("VBoxContainer/ErrorLabel")
+
+	var settled := false
+	for i in range(50):  # up to ~5s at 100ms/frame-ish via process_frame waits
+		await process_frame
+		if world_list_node.visible or empty_label.visible or error_label.visible:
+			settled = true
+			break
+
+	if _check("reached a real end state (cards, empty, or error) not stuck loading", settled):
+		passed += 1
+	else:
+		failed += 1
+		print("  world_list.visible=%s empty_label.visible=%s error_label.visible=%s" % [
+			world_list_node.visible, empty_label.visible, error_label.visible
+		])
+
+	if error_label.visible:
+		printerr("  Note: ended in error state: ", error_label.text)
+	elif world_list_node.visible:
+		print("  Note: rendered %d world card(s)" % world_list_node.get_child_count())
+	elif empty_label.visible:
+		print("  Note: ended in empty-list state")
+
+	# --- Summary ---
+	print("\n=== SMOKE RESULT: %d/%d passed ===" % [passed, passed + failed])
+	if failed > 0:
+		quit(1)
+	else:
+		print("SMOKE RESULT: ALL PASS")
+		quit(0)
+
+
+func _check(description: String, condition: bool) -> bool:
+	if condition:
+		print("  PASS: ", description)
+		return true
+	else:
+		printerr("  FAIL: ", description)
+		return false

scripts/world_list.gd

@@ -0,0 +1,135 @@
+extends Control
+## World list screen — browses public worlds via GET /api/worlds.
+##
+## Displays a scrollable list of world cards (name + description).
+## Handles loading, empty list, errors, and refresh.
+
+
+# UI references
+@onready var scroll_container: ScrollContainer = $VBoxContainer/ScrollContainer
+@onready var world_list: VBoxContainer = $VBoxContainer/ScrollContainer/WorldList
+@onready var loading_label: Label = $VBoxContainer/LoadingLabel
+@onready var error_label: Label = $VBoxContainer/ErrorLabel
+@onready var refresh_button: Button = $VBoxContainer/HeaderHBox/RefreshButton
+@onready var back_button: Button = $VBoxContainer/HeaderHBox/BackButton
+@onready var empty_label: Label = $VBoxContainer/EmptyLabel
+
+
+func _ready() -> void:
+	refresh_button.disabled = false
+	back_button.disabled = false
+	loading_label.visible = false
+	error_label.visible = false
+	empty_label.visible = false
+	world_list.visible = false
+	_refresh_worlds()
+
+
+func _on_refresh_button_pressed() -> void:
+	_refresh_worlds()
+
+
+func _on_back_button_pressed() -> void:
+	get_tree().change_scene_to_file("res://scenes/main_menu.tscn")
+
+
+## Fetch the world list from the backend and update the UI.
+func _refresh_worlds() -> void:
+	# Reset UI state
+	loading_label.visible = true
+	error_label.visible = false
+	empty_label.visible = false
+	world_list.visible = false
+	refresh_button.disabled = true
+
+	# Clear previous world cards
+	for child in world_list.get_children():
+		child.queue_free()
+
+	var result := await ApiClient.get_worlds()
+
+	loading_label.visible = false
+	refresh_button.disabled = false
+
+	if not result.ok:
+		# Show error message (401, network failure, etc.)
+		error_label.text = "Error: %s" % result.detail
+		error_label.visible = true
+		empty_label.visible = false
+		world_list.visible = false
+		return
+
+	var data = result.data
+	if not data is Array:
+		error_label.text = "Unexpected response format."
+		error_label.visible = true
+		empty_label.visible = false
+		world_list.visible = false
+		return
+
+	if data.is_empty():
+		empty_label.text = "No worlds yet. Check back later!"
+		empty_label.visible = true
+		error_label.visible = false
+		world_list.visible = false
+		return
+
+	# Render world cards
+	world_list.visible = true
+	empty_label.visible = false
+	error_label.visible = false
+
+	for world_dict in data:
+		if not world_dict is Dictionary:
+			continue
+		var card := _create_world_card(world_dict)
+		world_list.add_child(card)
+
+
+## Create a visual card for a single world entry.
+func _create_world_card(world_dict: Dictionary) -> Control:
+	var card := VBoxContainer.new()
+	card.size_flags_horizontal = Control.SIZE_FILL
+	card.custom_minimum_size = Vector2(0, 80)
+	card.add_theme_constant_override("separation", 4)
+
+	var name_label := Label.new()
+	name_label.text = world_dict.get("name", "Unnamed World")
+	name_label.autowrap_mode = TextServer.AUTOWRAP_WORD
+	name_label.size_flags_horizontal = Control.SIZE_FILL
+	name_label.size_flags_vertical = Control.SIZE_SHRINK_BEGIN
+	name_label.add_theme_font_size_override("font_size", 18)
+
+	var desc_label := Label.new()
+	var description: String = str(world_dict.get("description", ""))
+	desc_label.text = description if description != "" else "No description."
+	desc_label.autowrap_mode = TextServer.AUTOWRAP_WORD
+	desc_label.size_flags_horizontal = Control.SIZE_FILL
+	desc_label.size_flags_vertical = Control.SIZE_EXPAND_FILL
+	desc_label.add_theme_font_size_override("font_size", 14)
+	desc_label.add_theme_color_override("font_color", Color(0.7, 0.7, 0.7, 1.0))
+
+	var meta_label := Label.new()
+	var visibility: String = str(world_dict.get("visibility", "public"))
+	var created: String = str(world_dict.get("created_at", ""))
+	meta_label.text = "Visibility: %s%s" % [visibility, " | Created: " + created if created != "" else ""]
+	meta_label.autowrap_mode = TextServer.AUTOWRAP_WORD
+	meta_label.size_flags_horizontal = Control.SIZE_FILL
+	meta_label.size_flags_vertical = Control.SIZE_SHRINK_BEGIN
+	meta_label.add_theme_font_size_override("font_size", 12)
+	meta_label.add_theme_color_override("font_color", Color(0.5, 0.5, 0.5, 1.0))
+
+	card.add_child(name_label)
+	card.add_child(desc_label)
+	card.add_child(meta_label)
+
+	# Subtle background for the card
+	var bg := ColorRect.new()
+	bg.color = Color(0.15, 0.15, 0.15, 1.0)
+	bg.size_flags_horizontal = Control.SIZE_FILL
+	bg.size_flags_vertical = Control.SIZE_FILL
+	bg.custom_minimum_size = Vector2(0, 80)
+	card.add_child(bg)
+	card.move_child(bg, 0)
+
+	return card