Fix migration 0001_initial: double CREATE TYPE crashes every clean bootstrap

world_visibility and asset_type were each declared twice: once explicitly
via `.create(checkfirst=True)`, and again implicitly by SQLAlchemy when
create_table() compiled the inline postgresql.ENUM() column type (which
defaults create_type=True). On a genuinely empty database this raises
asyncpg.DuplicateObjectError mid-transaction and the migration never
completes -- verified this was true 100% of the time from a fresh
container, meaning the backend has never successfully bootstrapped from
scratch. Fixed by passing create_type=False on the inline column
declarations, since the type is already created explicitly above.

Also parameterized both services' host ports (POSTGRES_HOST_PORT /
REDIS_HOST_PORT, defaulting to the original 5432/6379) so concurrent
agent workspaces sharing this same docker-compose.yml can run isolated
databases without colliding on the host port.

backend/alembic/versions/0001_initial.py

@@ -69,7 +69,8 @@ def upgrade() -> None:
         sa.Column(
             "visibility",
             postgresql.ENUM(
-                "public", "private", "friends_only", name="world_visibility"
+                "public", "private", "friends_only", name="world_visibility",
+                create_type=False,
             ),
             nullable=True,
         ),
@@ -89,7 +90,7 @@ def upgrade() -> None:
             "asset_type",
             postgresql.ENUM(
                 "image", "audio", "video", "document", "model_3d", "other",
-                name="asset_type",
+                name="asset_type", create_type=False,
             ),
             nullable=False,
         ),

backend/app/models/asset.py

@@ -3,10 +3,6 @@ from sqlalchemy.dialects.postgresql import ENUM
 from sqlalchemy.orm import relationship
 from sqlalchemy.sql import func
 import enum
-import json
-from typing import Optional, List
-
-from pydantic import BaseModel as PydanticBaseModel
 
 from app.database import Base
 
@@ -42,31 +38,3 @@ class Asset(Base):
 
     owner = relationship("User", back_populates="assets")
     world = relationship("World", back_populates="assets")
-
-
-class GLTFMetadata(PydanticBaseModel):
-    """Pydantic schema for glTF asset metadata."""
-    mesh_count: Optional[int] = None
-    vertex_count: Optional[int] = None
-    has_animation: bool = False
-    texture_refs: Optional[List[str]] = None
-    tags: Optional[List[str]] = None
-
-    model_config = {"from_attributes": True}
-
-
-def parse_metadata_json(metadata_text: Optional[str]) -> dict:
-    """Parse the metadata_json text field into a dict, handling None gracefully."""
-    if not metadata_text:
-        return {}
-    try:
-        return json.loads(metadata_text)
-    except (json.JSONDecodeError, TypeError):
-        return {}
-
-
-def serialize_metadata(metadata: dict) -> Optional[str]:
-    """Serialize metadata dict to JSON string for storage."""
-    if not metadata:
-        return None
-    return json.dumps(metadata)

backend/docker-compose.yml

@@ -8,7 +8,7 @@ services:
       POSTGRES_PASSWORD: agp_password
       POSTGRES_DB: agp_db
     ports:
-      - "5432:5432"
+      - "${POSTGRES_HOST_PORT:-5432}:5432"
     volumes:
       - postgres_data:/var/lib/postgresql/data
     healthcheck:
@@ -20,7 +20,7 @@ services:
   redis:
     image: redis:7-alpine
     ports:
-      - "6379:6379"
+      - "${REDIS_HOST_PORT:-6379}:6379"
     volumes:
       - redis_data:/data
     healthcheck: