Add multiplayer room event model and channel ID allocation

Introduces the MultiplayerRealtimeRoomEvent SQLModel for tracking real-time room events. Adds an async helper to allocate unique channel IDs for rooms, and updates room creation logic to use this helper for assigning channel IDs automatically.

app/database/multiplayer_realtime_room_event.py

@@ -0,0 +1,39 @@
+from datetime import datetime
+from typing import Optional, ClassVar
+
+from sqlalchemy import Text
+from sqlalchemy.ext.asyncio import AsyncAttrs
+from sqlmodel import SQLModel, Field, Column, DateTime, BigInteger, ForeignKey
+
+from app.models.model import UTCBaseModel
+from app.utils import utcnow
+
+
+class MultiplayerRealtimeRoomEventBase(SQLModel, UTCBaseModel):
+    event_type: str = Field(index=True)
+    event_detail: Optional[str] = Field(default=None, sa_column=Column(Text))
+
+
+class MultiplayerRealtimeRoomEvent(AsyncAttrs, MultiplayerRealtimeRoomEventBase, table=True):
+    __tablename__: ClassVar[str] = "multiplayer_realtime_room_event"
+
+    id: int | None = Field(default=None, primary_key=True, index=True)
+
+    room_id: int = Field(
+        sa_column=Column(ForeignKey("rooms.id"), index=True, nullable=False)
+    )
+    playlist_item_id: int | None = Field(
+        default=None,
+        sa_column=Column(ForeignKey("playlists.id"), index=True, nullable=True),
+    )
+    user_id: int | None = Field(
+        default=None,
+        sa_column=Column(BigInteger, ForeignKey("lazer_users.id"), index=True, nullable=True),
+    )
+
+    created_at: datetime = Field(
+        sa_column=Column(DateTime(timezone=True)), default_factory=utcnow
+    )
+    updated_at: datetime = Field(
+        sa_column=Column(DateTime(timezone=True)), default_factory=utcnow
+    )