WIP checkpoint: T1: Moderation data model + Alembic migration

backend/alembic/env.py

@@ -8,7 +8,7 @@ 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
+from app.models import user, session, world, asset, moderation  # noqa: F401
 
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.

backend/alembic/versions/0003_add_moderation_schema.py

@@ -1,6 +1,6 @@
-"""trust & safety: reports, moderation_actions, appeals + user role/ban/suspend
+"""add moderation schema
 
-Revision ID: 0003_trust_safety
+Revision ID: 0003_add_moderation_schema
 Revises: 0002_add_date_of_birth_to_users
 Create Date: 2025-01-01 00:00:00.000000
 
@@ -12,79 +12,69 @@ import sqlalchemy as sa
 from sqlalchemy.dialects import postgresql
 
 # revision identifiers, used by Alembic.
-revision: str = "0003_trust_safety"
+revision: str = "0003_add_moderation_schema"
 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 trust & safety tables and extend users table."""
+    """Create moderation tables and extend users table."""
-    bind = op.get_bind()
+    # ── ENUM types ──────────────────────────────────────────────
 
-    # ── ENUM types ──────────────────────────────────────────────────────
+    target_type_enum = postgresql.ENUM(
-
+        "user", "world", "asset", "chat_message",
-    # user_role
+        name="target_type",
-    user_role = postgresql.ENUM("user", "moderator", "admin", name="user_role")
-    user_role.create(bind, checkfirst=True)
-
-    # report_target_type
-    report_target_type = postgresql.ENUM(
-        "user", "world", "asset", "chat_message", name="report_target_type"
     )
-    report_target_type.create(bind, checkfirst=True)
+    target_type_enum.create(op.get_bind(), checkfirst=True)
 
-    # reason_category
+    reason_category_enum = postgresql.ENUM(
-    reason_category = postgresql.ENUM(
+        "harassment", "hate_speech", "sexual_content", "violence",
-        "harassment",
+        "spam", "self_harm", "other",
-        "hate_speech",
-        "sexual_content",
-        "violence",
-        "spam",
-        "self_harm",
-        "other",
         name="reason_category",
     )
-    reason_category.create(bind, checkfirst=True)
+    reason_category_enum.create(op.get_bind(), checkfirst=True)
 
-    # report_status
+    report_status_enum = postgresql.ENUM(
-    report_status = postgresql.ENUM(
+        "open", "in_review", "resolved", "dismissed",
-        "open", "in_review", "resolved", "dismissed", name="report_status"
+        name="report_status",
     )
-    report_status.create(bind, checkfirst=True)
+    report_status_enum.create(op.get_bind(), checkfirst=True)
 
-    # resolution
     resolution_enum = postgresql.ENUM(
-        "action_taken", "no_action", "false_positive", name="resolution"
+        "upheld", "modified", "dismissed",
+        name="resolution",
     )
-    resolution_enum.create(bind, checkfirst=True)
+    resolution_enum.create(op.get_bind(), checkfirst=True)
 
-    # moderation_action_type
+    moderation_action_type_enum = postgresql.ENUM(
-    moderation_action_type = postgresql.ENUM(
         "warn", "suspend", "ban", "restrict", "remove", "restore",
         name="moderation_action_type",
     )
-    moderation_action_type.create(bind, checkfirst=True)
+    moderation_action_type_enum.create(op.get_bind(), checkfirst=True)
 
-    # moderation_target_type
+    appeal_status_enum = postgresql.ENUM(
-    moderation_target_type = postgresql.ENUM(
+        "pending", "approved", "rejected",
-        "user", "world", "asset", "chat_message", name="moderation_target_type"
+        name="appeal_status",
     )
-    moderation_target_type.create(bind, checkfirst=True)
+    appeal_status_enum.create(op.get_bind(), checkfirst=True)
 
-    # appeal_status
+    user_role_enum = postgresql.ENUM(
-    appeal_status = postgresql.ENUM(
+        "user", "moderator", "admin",
-        "pending", "approved", "rejected", name="appeal_status"
+        name="user_role",
     )
-    appeal_status.create(bind, checkfirst=True)
+    user_role_enum.create(op.get_bind(), checkfirst=True)
 
-    # ── Extend users table ──────────────────────────────────────────────
+    # ── users table extensions ──────────────────────────────────
 
     op.add_column(
         "users",
         sa.Column(
             "role",
-            postgresql.ENUM("user", "moderator", "admin", name="user_role"),
+            postgresql.ENUM(
+                "user", "moderator", "admin", name="user_role",
+                create_type=False,
+            ),
             nullable=False,
             server_default="user",
         ),
@@ -98,16 +88,17 @@ def upgrade() -> None:
         sa.Column("suspended_until", sa.DateTime(timezone=True), nullable=True),
     )
 
-    # ── reports table ───────────────────────────────────────────────────
+    # ── reports table ───────────────────────────────────────────
 
     op.create_table(
         "reports",
-        sa.Column("id", sa.BigInteger(), primary_key=True, autoincrement=True),
+        sa.Column("id", sa.Integer(), primary_key=True),
         sa.Column("reporter_id", sa.Integer(), nullable=False),
         sa.Column(
             "target_type",
             postgresql.ENUM(
-                "user", "world", "asset", "chat_message", name="report_target_type"
+                "user", "world", "asset", "chat_message",
+                name="target_type", create_type=False,
             ),
             nullable=False,
         ),
@@ -115,24 +106,18 @@ def upgrade() -> None:
         sa.Column(
             "reason_category",
             postgresql.ENUM(
-                "harassment",
+                "harassment", "hate_speech", "sexual_content", "violence",
-                "hate_speech",
+                "spam", "self_harm", "other",
-                "sexual_content",
+                name="reason_category", create_type=False,
-                "violence",
-                "spam",
-                "self_harm",
-                "other",
-                name="reason_category",
             ),
             nullable=False,
         ),
-        sa.Column(
+        sa.Column("details", sa.Text(), nullable=True),
-            "details", sa.Text(), nullable=True,
-        ),
         sa.Column(
             "status",
             postgresql.ENUM(
-                "open", "in_review", "resolved", "dismissed", name="report_status"
+                "open", "in_review", "resolved", "dismissed",
+                name="report_status", create_type=False,
             ),
             nullable=False,
             server_default="open",
@@ -141,11 +126,11 @@ def upgrade() -> None:
         sa.Column(
             "resolution",
             postgresql.ENUM(
-                "action_taken", "no_action", "false_positive", name="resolution"
+                "upheld", "modified", "dismissed",
+                name="resolution", create_type=False,
             ),
             nullable=True,
         ),
-        sa.Column("resolved_at", sa.DateTime(timezone=True), nullable=True),
         sa.Column(
             "created_at",
             sa.DateTime(timezone=True),
@@ -155,45 +140,49 @@ def upgrade() -> None:
         sa.Column(
             "updated_at",
             sa.DateTime(timezone=True),
-            onupdate=sa.func.now(),
+            server_default=sa.func.now(),
-            nullable=True,
+            nullable=False,
         ),
-        sa.ForeignKeyConstraint(["reporter_id"], ["users.id"], ondelete="CASCADE"),
+        sa.Column("resolved_at", sa.DateTime(timezone=True), nullable=True),
-        sa.ForeignKeyConstraint(["resolved_by"], ["users.id"], ondelete="SET NULL"),
+        sa.ForeignKeyConstraint(
-        sa.UniqueConstraint(
+            ["reporter_id"], ["users.id"], ondelete="CASCADE",
-            "reporter_id", "target_type", "target_id",
+        ),
-            name="uq_reporter_target",
+        sa.ForeignKeyConstraint(
+            ["resolved_by"], ["users.id"], ondelete="SET NULL",
         ),
     )
     op.create_index(op.f("ix_reports_id"), "reports", ["id"], unique=False)
     op.create_index(
-        op.f("ix_reports_reporter_id"), "reports", ["reporter_id"], unique=False
+        op.f("ix_reports_reporter_id"), "reports", ["reporter_id"], unique=False,
     )
     op.create_index(
-        op.f("ix_reports_status"), "reports", ["status"], unique=False
+        op.f("ix_reports_status"), "reports", ["status"], unique=False,
+    )
+    op.create_index(
+        op.f("ix_reports_target"), "reports", ["target_type", "target_id"], unique=False,
     )
 
-    # ── moderation_actions table ────────────────────────────────────────
+    # ── moderation_actions table ────────────────────────────────
 
     op.create_table(
         "moderation_actions",
-        sa.Column("id", sa.BigInteger(), primary_key=True, autoincrement=True),
+        sa.Column("id", sa.Integer(), primary_key=True),
         sa.Column("moderator_id", sa.Integer(), nullable=False),
-        sa.Column("target_user_id", sa.Integer(), nullable=True),
+        sa.Column("target_user_id", sa.Integer(), nullable=False),
         sa.Column(
             "target_type",
             postgresql.ENUM(
                 "user", "world", "asset", "chat_message",
-                name="moderation_target_type",
+                name="target_type", create_type=False,
             ),
             nullable=False,
         ),
-        sa.Column("target_id", sa.String(length=64), nullable=True),
+        sa.Column("target_id", sa.String(length=64), nullable=False),
         sa.Column(
             "action",
             postgresql.ENUM(
                 "warn", "suspend", "ban", "restrict", "remove", "restore",
-                name="moderation_action_type",
+                name="moderation_action_type", create_type=False,
             ),
             nullable=False,
         ),
@@ -207,51 +196,48 @@ def upgrade() -> None:
             server_default=sa.func.now(),
             nullable=False,
         ),
-        sa.ForeignKeyConstraint(["moderator_id"], ["users.id"], ondelete="CASCADE"),
         sa.ForeignKeyConstraint(
-            ["target_user_id"], ["users.id"], ondelete="CASCADE"
+            ["moderator_id"], ["users.id"], ondelete="SET NULL",
+        ),
+        sa.ForeignKeyConstraint(
+            ["target_user_id"], ["users.id"], ondelete="CASCADE",
+        ),
+        sa.ForeignKeyConstraint(
+            ["report_id"], ["reports.id"], ondelete="SET NULL",
         ),
-        sa.ForeignKeyConstraint(["report_id"], ["reports.id"], ondelete="SET NULL"),
     )
     op.create_index(
         op.f("ix_moderation_actions_id"),
-        "moderation_actions",
+        "moderation_actions", ["id"], unique=False,
-        ["id"],
-        unique=False,
     )
     op.create_index(
         op.f("ix_moderation_actions_moderator_id"),
-        "moderation_actions",
+        "moderation_actions", ["moderator_id"], unique=False,
-        ["moderator_id"],
-        unique=False,
     )
     op.create_index(
         op.f("ix_moderation_actions_target_user_id"),
-        "moderation_actions",
+        "moderation_actions", ["target_user_id"], unique=False,
-        ["target_user_id"],
-        unique=False,
     )
     op.create_index(
-        op.f("ix_moderation_actions_report_id"),
+        op.f("ix_moderation_actions_target"),
-        "moderation_actions",
+        "moderation_actions", ["target_type", "target_id"], unique=False,
-        ["report_id"],
-        unique=False,
     )
 
-    # ── appeals table ───────────────────────────────────────────────────
+    # ── appeals table ───────────────────────────────────────────
 
     op.create_table(
         "appeals",
-        sa.Column("id", sa.BigInteger(), primary_key=True, autoincrement=True),
+        sa.Column("id", sa.Integer(), primary_key=True),
         sa.Column(
-            "moderation_action_id", sa.Integer(), nullable=False
+            "moderation_action_id", sa.Integer(), nullable=False,
         ),
         sa.Column("user_id", sa.Integer(), nullable=False),
         sa.Column("reason", sa.Text(), nullable=False),
         sa.Column(
             "status",
             postgresql.ENUM(
-                "pending", "approved", "rejected", name="appeal_status"
+                "pending", "approved", "rejected",
+                name="appeal_status", create_type=False,
             ),
             nullable=False,
             server_default="pending",
@@ -266,49 +252,45 @@ def upgrade() -> None:
         ),
         sa.ForeignKeyConstraint(
             ["moderation_action_id"],
-            ["moderation_actions.id"],
+            ["moderation_actions.id"], ondelete="CASCADE",
-            ondelete="CASCADE",
         ),
-        sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="CASCADE"),
         sa.ForeignKeyConstraint(
-            ["reviewed_by"], ["users.id"], ondelete="SET NULL"
+            ["user_id"], ["users.id"], ondelete="CASCADE",
+        ),
+        sa.ForeignKeyConstraint(
+            ["reviewed_by"], ["users.id"], ondelete="SET NULL",
         ),
     )
     op.create_index(op.f("ix_appeals_id"), "appeals", ["id"], unique=False)
     op.create_index(
         op.f("ix_appeals_moderation_action_id"),
-        "appeals",
+        "appeals", ["moderation_action_id"], unique=False,
-        ["moderation_action_id"],
-        unique=False,
     )
     op.create_index(
         op.f("ix_appeals_user_id"),
-        "appeals",
+        "appeals", ["user_id"], unique=False,
-        ["user_id"],
-        unique=False,
     )
     op.create_index(
         op.f("ix_appeals_status"),
-        "appeals",
+        "appeals", ["status"], unique=False,
-        ["status"],
-        unique=False,
     )
 
 
 def downgrade() -> None:
-    """Remove trust & safety tables and revert users table."""
+    """Drop moderation tables and revert users table."""
     op.drop_index(op.f("ix_appeals_status"), table_name="appeals")
     op.drop_index(op.f("ix_appeals_user_id"), table_name="appeals")
     op.drop_index(op.f("ix_appeals_moderation_action_id"), table_name="appeals")
     op.drop_index(op.f("ix_appeals_id"), table_name="appeals")
     op.drop_table("appeals")
 
-    op.drop_index(op.f("ix_moderation_actions_report_id"), table_name="moderation_actions")
+    op.drop_index(op.f("ix_moderation_actions_target"), table_name="moderation_actions")
     op.drop_index(op.f("ix_moderation_actions_target_user_id"), table_name="moderation_actions")
     op.drop_index(op.f("ix_moderation_actions_moderator_id"), table_name="moderation_actions")
     op.drop_index(op.f("ix_moderation_actions_id"), table_name="moderation_actions")
     op.drop_table("moderation_actions")
 
+    op.drop_index(op.f("ix_reports_target"), table_name="reports")
     op.drop_index(op.f("ix_reports_status"), table_name="reports")
     op.drop_index(op.f("ix_reports_reporter_id"), table_name="reports")
     op.drop_index(op.f("ix_reports_id"), table_name="reports")
@@ -319,11 +301,10 @@ def downgrade() -> None:
     op.drop_column("users", "role")
 
     # Drop ENUM types
-    postgresql.ENUM(name="appeal_status").drop(bind, checkfirst=True)
+    postgresql.ENUM(name="appeal_status").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="moderation_target_type").drop(bind, checkfirst=True)
+    postgresql.ENUM(name="moderation_action_type").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="moderation_action_type").drop(bind, checkfirst=True)
+    postgresql.ENUM(name="resolution").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="resolution").drop(bind, checkfirst=True)
+    postgresql.ENUM(name="report_status").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="report_status").drop(bind, checkfirst=True)
+    postgresql.ENUM(name="reason_category").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="reason_category").drop(bind, checkfirst=True)
+    postgresql.ENUM(name="target_type").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="report_target_type").drop(bind, checkfirst=True)
+    postgresql.ENUM(name="user_role").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="user_role").drop(bind, checkfirst=True)

backend/app/models/__init__.py

@@ -2,8 +2,30 @@ from app.models.user import User
 from app.models.session import Session
 from app.models.world import World
 from app.models.asset import Asset
-from app.models.report import Report
+from app.models.moderation import (
-from app.models.moderation_action import ModerationAction
+    Report,
-from app.models.appeal import Appeal
+    ModerationAction,
+    Appeal,
+    TargetType,
+    ReasonCategory,
+    ReportStatus,
+    Resolution,
+    ModerationActionType,
+    AppealStatus,
+)
 
-__all__ = ["User", "Session", "World", "Asset", "Report", "ModerationAction", "Appeal"]
+__all__ = [
+    "User",
+    "Session",
+    "World",
+    "Asset",
+    "Report",
+    "ModerationAction",
+    "Appeal",
+    "TargetType",
+    "ReasonCategory",
+    "ReportStatus",
+    "Resolution",
+    "ModerationActionType",
+    "AppealStatus",
+]

backend/app/models/appeal.py

@@ -1,47 +0,0 @@
-"""Appeal model for Trust & Safety."""
-
-from datetime import datetime
-from typing import Optional
-
-from sqlalchemy import (
-    Column,
-    Integer,
-    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 AppealStatus(str, enum.Enum):
-    PENDING = "pending"
-    APPROVED = "approved"
-    REJECTED = "rejected"
-
-
-class Appeal(Base):
-    __tablename__ = "appeals"
-
-    id = Column(Integer, primary_key=True, autoincrement=True)
-    moderation_action_id = Column(
-        Integer, ForeignKey("moderation_actions.id", ondelete="CASCADE"), nullable=False
-    )
-    user_id = Column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False)
-    reason = Column(Text, nullable=False)
-    status = Column(
-        ENUM(AppelStatus, name="appeal_status", create_type=False),
-        default=AppealStatus.PENDING,
-    )
-    reviewed_by = Column(Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
-    reviewed_at = Column(DateTime(timezone=True), nullable=True)
-    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
-
-    # Relationships
-    moderation_action = relationship("ModerationAction", back_populates="appeals")
-    user = relationship("User", foreign_keys=[user_id])
-    reviewer = relationship("User", foreign_keys=[reviewed_by])

backend/app/models/moderation.py

@@ -0,0 +1,186 @@
+"""Moderation data models for Trust & Safety."""
+
+import enum
+from datetime import datetime
+from typing import Optional
+
+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
+
+from app.database import Base
+
+
+class TargetType(str, enum.Enum):
+    """Type of entity being reported or moderated."""
+    USER = "user"
+    WORLD = "world"
+    ASSET = "asset"
+    CHAT_MESSAGE = "chat_message"
+
+
+class ReasonCategory(str, enum.Enum):
+    """Category of reason for a report."""
+    HARASSMENT = "harassment"
+    HATE_SPEECH = "hate_speech"
+    SEXUAL_CONTENT = "sexual_content"
+    VIOLENCE = "violence"
+    SPAM = "spam"
+    SELF_HARM = "self_harm"
+    OTHER = "other"
+
+
+class ReportStatus(str, enum.Enum):
+    """Status of a report."""
+    OPEN = "open"
+    IN_REVIEW = "in_review"
+    RESOLVED = "resolved"
+    DISMISSED = "dismissed"
+
+
+class Resolution(str, enum.Enum):
+    """Resolution outcome of a report."""
+    UPHELD = "upheld"
+    MODIFIED = "modified"
+    DISMISSED = "dismissed"
+
+
+class ModerationActionType(str, enum.Enum):
+    """Type of moderation action taken."""
+    WARN = "warn"
+    SUSPEND = "suspend"
+    BAN = "ban"
+    RESTRICT = "restrict"
+    REMOVE = "remove"
+    RESTORE = "restore"
+
+
+class AppealStatus(str, enum.Enum):
+    """Status of an appeal."""
+    PENDING = "pending"
+    APPROVED = "approved"
+    REJECTED = "rejected"
+
+
+class Report(Base):
+    """A report filed by a user against a target entity."""
+    __tablename__ = "reports"
+
+    id = Column(Integer, primary_key=True, index=True)
+    reporter_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False
+    )
+    target_type = Column(
+        ENUM(TargetType, name="target_type", create_type=False),
+        nullable=False,
+    )
+    target_id = Column(String(64), nullable=False)
+    reason_category = Column(
+        ENUM(ReasonCategory, name="reason_category", create_type=False),
+        nullable=False,
+    )
+    details = Column(Text, nullable=True)
+    status = Column(
+        ENUM(ReportStatus, name="report_status", create_type=False),
+        default=ReportStatus.OPEN,
+        nullable=False,
+    )
+    resolved_by = Column(
+        Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True
+    )
+    resolution = Column(
+        ENUM(Resolution, name="resolution", create_type=False),
+        nullable=True,
+    )
+    created_at = Column(
+        DateTime(timezone=True), server_default=func.now(), nullable=False
+    )
+    updated_at = Column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        onupdate=func.now(),
+        nullable=False,
+    )
+    resolved_at = Column(DateTime(timezone=True), nullable=True)
+
+    # Relationships
+    reporter = relationship("User", foreign_keys=[reporter_id])
+    resolver = relationship("User", foreign_keys=[resolved_by])
+    moderation_actions = relationship(
+        "ModerationAction", back_populates="report", cascade="all, delete-orphan"
+    )
+    appeals = relationship(
+        "Appeal", back_populates="report", cascade="all, delete-orphan"
+    )
+
+
+class ModerationAction(Base):
+    """A moderation action taken by a moderator against a user or entity."""
+    __tablename__ = "moderation_actions"
+
+    id = Column(Integer, primary_key=True, index=True)
+    moderator_id = Column(
+        Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=False
+    )
+    target_user_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False
+    )
+    target_type = Column(
+        ENUM(TargetType, name="target_type", create_type=False),
+        nullable=False,
+    )
+    target_id = Column(String(64), nullable=False)
+    action = Column(
+        ENUM(ModerationActionType, name="moderation_action_type", create_type=False),
+        nullable=False,
+    )
+    reason = Column(Text, nullable=True)
+    report_id = Column(
+        Integer, ForeignKey("reports.id", ondelete="SET NULL"), nullable=True
+    )
+    expires_at = Column(DateTime(timezone=True), nullable=True)
+    revoked_at = Column(DateTime(timezone=True), nullable=True)
+    created_at = Column(
+        DateTime(timezone=True), server_default=func.now(), nullable=False
+    )
+
+    # Relationships
+    moderator = relationship("User", foreign_keys=[moderator_id])
+    target_user = relationship("User", foreign_keys=[target_user_id])
+    report = relationship("Report", back_populates="moderation_actions")
+    appeals = relationship(
+        "Appeal", back_populates="moderation_action", cascade="all, delete-orphan"
+    )
+
+
+class Appeal(Base):
+    """An appeal filed by a user against a moderation action."""
+    __tablename__ = "appeals"
+
+    id = Column(Integer, primary_key=True, index=True)
+    moderation_action_id = Column(
+        Integer, ForeignKey("moderation_actions.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    user_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False
+    )
+    reason = Column(Text, nullable=False)
+    status = Column(
+        ENUM(AppealStatus, name="appeal_status", create_type=False),
+        default=AppealStatus.PENDING,
+        nullable=False,
+    )
+    reviewed_by = Column(
+        Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True
+    )
+    reviewed_at = Column(DateTime(timezone=True), nullable=True)
+    created_at = Column(
+        DateTime(timezone=True), server_default=func.now(), nullable=False
+    )
+
+    # Relationships
+    moderation_action = relationship("ModerationAction", back_populates="appeals")
+    user = relationship("User", foreign_keys=[user_id])
+    reviewer = relationship("User", foreign_keys=[reviewed_by])

backend/app/models/moderation_action.py

@@ -1,63 +0,0 @@
-"""ModerationAction model for Trust & Safety."""
-
-from datetime import datetime
-from typing import Optional
-
-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 ModerationActionType(str, enum.Enum):
-    WARN = "warn"
-    SUSPEND = "suspend"
-    BAN = "ban"
-    RESTRICT = "restrict"
-    REMOVE = "remove"
-    RESTORE = "restore"
-
-
-class ModerationTargetType(str, enum.Enum):
-    USER = "user"
-    WORLD = "world"
-    ASSET = "asset"
-    CHAT_MESSAGE = "chat_message"
-
-
-class ModerationAction(Base):
-    __tablename__ = "moderation_actions"
-
-    id = Column(Integer, primary_key=True, autoincrement=True)
-    moderator_id = Column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False)
-    target_user_id = Column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=True)
-    target_type = Column(
-        ENUM(ModerationTargetType, name="moderation_target_type", create_type=False),
-        nullable=False,
-    )
-    target_id = Column(String(64), nullable=True)
-    action = Column(
-        ENUM(ModerationActionType, name="moderation_action_type", create_type=False),
-        nullable=False,
-    )
-    reason = Column(Text, nullable=True)
-    report_id = Column(Integer, ForeignKey("reports.id", ondelete="SET NULL"), nullable=True)
-    expires_at = Column(DateTime(timezone=True), nullable=True)
-    revoked_at = Column(DateTime(timezone=True), nullable=True)
-    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
-
-    # Relationships
-    moderator = relationship("User", foreign_keys=[moderator_id])
-    target_user = relationship("User", foreign_keys=[target_user_id])
-    report = relationship("Report", foreign_keys=[report_id])
-    appeals = relationship("Appeal", back_populates="moderation_action", cascade="all, delete-orphan")

backend/app/models/report.py

@@ -1,88 +0,0 @@
-"""Report model for Trust & Safety."""
-
-from datetime import datetime
-from typing import Optional
-
-from sqlalchemy import (
-    Column,
-    Integer,
-    String,
-    Text,
-    DateTime,
-    ForeignKey,
-    UniqueConstraint,
-)
-from sqlalchemy.dialects.postgresql import ENUM
-from sqlalchemy.orm import relationship
-from sqlalchemy.sql import func
-import enum
-
-from app.database import Base
-
-
-class ReportTargetType(str, enum.Enum):
-    USER = "user"
-    WORLD = "world"
-    ASSET = "asset"
-    CHAT_MESSAGE = "chat_message"
-
-
-class ReasonCategory(str, enum.Enum):
-    HARASSMENT = "harassment"
-    HATE_SPEECH = "hate_speech"
-    SEXUAL_CONTENT = "sexual_content"
-    VIOLENCE = "violence"
-    SPAM = "spam"
-    SELF_HARM = "self_harm"
-    OTHER = "other"
-
-
-class ReportStatus(str, enum.Enum):
-    OPEN = "open"
-    IN_REVIEW = "in_review"
-    RESOLVED = "resolved"
-    DISMISSED = "dismissed"
-
-
-class Resolution(str, enum.Enum):
-    ACTION_TAKEN = "action_taken"
-    NO_ACTION = "no_action"
-    FALSE_POSITIVE = "false_positive"
-
-
-class Report(Base):
-    __tablename__ = "reports"
-
-    id = Column(Integer, primary_key=True, autoincrement=True)
-    reporter_id = Column(Integer, ForeignKey("users.id"), nullable=False)
-    target_type = Column(
-        ENUM(ReportTargetType, name="report_target_type", create_type=False),
-        nullable=False,
-    )
-    target_id = Column(String(64), nullable=False)
-    reason_category = Column(
-        ENUM(ReasonCategory, name="reason_category", create_type=False),
-        nullable=False,
-    )
-    details = Column(Text, nullable=True)
-    status = Column(
-        ENUM(ReportStatus, name="report_status", create_type=False),
-        default=ReportStatus.OPEN,
-    )
-    resolved_by = Column(Integer, ForeignKey("users.id"), nullable=True)
-    resolution = Column(
-        ENUM(Resolution, name="resolution", create_type=False),
-        nullable=True,
-    )
-    resolved_at = Column(DateTime(timezone=True), nullable=True)
-    created_at = Column(DateTime(timezone=True), server_default=func.now())
-    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
-
-    # Relationships
-    reporter = relationship("User", foreign_keys=[reporter_id])
-    resolved_by_user = relationship("User", foreign_keys=[resolved_by])
-
-    __table_args__ = (
-        UniqueConstraint("reporter_id", "target_type", "target_id",
-                         name="uq_reporter_target"),
-    )

backend/app/models/user.py

@@ -1,15 +1,16 @@
 from datetime import date
 from typing import Optional
 
-from sqlalchemy import Column, Integer, String, Boolean, DateTime, Date, Enum
+from sqlalchemy import Column, Integer, String, Boolean, DateTime, Date, func
+from sqlalchemy.dialects.postgresql import ENUM
 from sqlalchemy.orm import relationship
-from sqlalchemy.sql import func
 import enum
 
 from app.database import Base
 
 
 class UserRole(str, enum.Enum):
+    """User role for moderation and access control."""
     USER = "user"
     MODERATOR = "moderator"
     ADMIN = "admin"
@@ -25,9 +26,9 @@ class User(Base):
     date_of_birth = Column(Date, nullable=True)
     is_active = Column(Boolean, default=True)
     role = Column(
-        Enum(UserRole, name="user_role"),
+        ENUM(UserRole, name="user_role", create_type=False),
+        default=UserRole.USER,
         nullable=False,
-        server_default="user",
     )
     banned_until = Column(DateTime(timezone=True), nullable=True)
     suspended_until = Column(DateTime(timezone=True), nullable=True)
@@ -37,11 +38,6 @@ class User(Base):
     sessions = relationship("Session", back_populates="user", cascade="all, delete-orphan")
     worlds = relationship("World", back_populates="owner")
     assets = relationship("Asset", back_populates="owner")
-    reports_made = relationship("Report", foreign_keys="Report.reporter_id", back_populates="reporter")
-    reports_resolved = relationship("Report", foreign_keys="Report.resolved_by", back_populates="resolved_by_user")
-    moderation_actions_as_moderator = relationship("ModerationAction", foreign_keys="ModerationAction.moderator_id", back_populates="moderator")
-    moderation_actions_as_target = relationship("ModerationAction", foreign_keys="ModerationAction.target_user_id", back_populates="target_user")
-    appeals = relationship("Appeal", foreign_keys="Appeal.user_id", back_populates="user")
 
     @property
     def is_adult(self) -> bool: