feat(discovery): world discovery metadata and world_visits model with migration 0015

backend/app/routers/worlds.py

@@ -27,6 +27,8 @@ class WorldCreate(BaseModel):
     name: str = Field(..., min_length=1, max_length=255)
     description: str | None = None
     visibility: WorldVisibility = WorldVisibility.PUBLIC
+    category: str | None = None
+    tags: list[str] | None = None
 
 
 class WorldUpdate(BaseModel):
@@ -34,6 +36,8 @@ class WorldUpdate(BaseModel):
     name: str | None = Field(None, min_length=1, max_length=255)
     description: str | None = None
     visibility: WorldVisibility | None = None
+    category: str | None = None
+    tags: list[str] | None = None
 
 
 class WorldResponse(BaseModel):
@@ -42,12 +46,17 @@ class WorldResponse(BaseModel):
     name: str
     description: str | None
     visibility: WorldVisibility
+    category: str | None = None
+    tags: list[str] | None = None
+    play_count: int = 0
+    last_played_at: datetime | None = None
     owner_id: int
     created_at: datetime | None = None
 
     model_config = {"from_attributes": True}
 
 
+
 # --- Endpoints ---
 
 @router.get("/", response_model=list[WorldResponse])
@@ -159,7 +168,10 @@ async def create_world(
         description=world_data.description,
         owner_id=current_user.id,
         visibility=world_data.visibility,
+        category=world_data.category,
+        tags=world_data.tags or [],
     )
+
     db.add(world)
     await db.flush()  # assigns world.id, needed for the room's FK
     await WorldStore(db).get_or_create_main_room(world.id)