Phase 5: Complete Core Game Engine implementation

- Added MTGOnlineGame, GamePlayer, GameHistory models
- Implemented full game CRUD endpoints (create, list, get, join, leave, start, end)
- Integrated WebSocket game server with database persistence
- Added Commander deck validation service (100-card min, color identity, ban list)
- Created Alembic migration 006 for new game tables
- All game endpoints now database-backed (no more stubs)

backend/alembic/env.py

@@ -15,17 +15,15 @@ from alembic import context
 from app.core.database import Base
 from app.models import (
     User, DecklistFile, DecklistFolder, Room, RoomGameType,
-    Ban, GameLog, AuditLog, MtgCardMirror, DeckCardLink
-)
-# Import new models
-from app.models.user_data import (
+    Ban, GameLog, AuditLog, MtgonlineCard, DeckCardLink,
+    UserDeck, UserDeckCard, DeckPrecedent, DeckPrecedentCard, CardSuggestion,
     UserSession, DeckVersion, GameReplay, ReplayPlayer,
     GameOutcome, UserStatistics, UserCardCollection, CardWishlist,
     UserGroup, GroupMember, GroupChatMessage, UserNetwork,
-    NetworkMember, UserPreference, UserActivityLog
+    NetworkMember, UserPreference, UserActivityLog,
+    CardImportBatch, UserCardImportRecord, UserCardImport,
+    MTGOnlineGame, GamePlayer, GameHistory
 )
-from app.models.user_deck import UserDeck, UserDeckCard, DeckPrecedent, DeckPrecedentCard, CardSuggestion
-from app.models.user_card_import import UserCardImport
 
 # this is the Alembic Config object
 config = context.config