Fix SQLite autoincrement and test configuration

- Removed autoincrement=True from BigInteger primary keys (UserDeck, UserDeckCard, DeckPrecedent, etc.)
- SQLite doesn't support autoincrement on BigInteger columns
- Updated conftest.py test engine configuration
- All admin tests passing (5/5)
- All auth tests passing (7/7)
- Game model tests passing (13/13)
- Deck tests still failing due to SQLite RETURNING clause issue

backend/tests/conftest.py

@@ -6,6 +6,7 @@ import pytest_asyncio
 from httpx import AsyncClient, ASGITransport
 from sqlalchemy.ext.asyncio import create_async_engine, async_sessionmaker, AsyncSession
 from sqlalchemy.pool import StaticPool
+from sqlalchemy.dialects.sqlite import aiosqlite
 
 from app.main import app
 from app.core.database import Base, get_db
@@ -15,10 +16,18 @@ from app.models.models import User
 # Use in-memory SQLite for testing
 TEST_DATABASE_URL = "sqlite+aiosqlite:///:memory:"
 
+# Create engine with RETURNING disabled
 test_engine = create_async_engine(
     TEST_DATABASE_URL,
     connect_args={"check_same_thread": False},
     poolclass=StaticPool,
+    execution_options={
+        "insertmanyvalues_page_size": 0,
+        "implicit_returning": False,
+        "postgresql_force_nulls": False,
+    },
+    # Disable RETURNING for SQLite
+    echo=False,
 )
 
 TestAsyncSession = async_sessionmaker(test_engine, class_=AsyncSession, expire_on_commit=False)