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/app/services/deck_manager.py

@@ -1,7 +1,7 @@
 """Deck manager service."""
 from typing import List, Dict, Any, Optional
 from sqlalchemy.ext.asyncio import AsyncSession
-from sqlalchemy import select, update, delete
+from sqlalchemy import select, update, delete, func, text
 from sqlalchemy.orm import selectinload
 
 from app.models.models import UserDeck, UserDeckCard, DeckPrecedent, DeckPrecedentCard, MtgonlineCard
@@ -21,19 +21,32 @@ class DeckManager:
         is_precedent: bool = False,
         precedent_name: Optional[str] = None,
     ) -> UserDeck:
-        """Create a new deck."""
-        deck = UserDeck(
+        """Create a new deck using ORM approach.
+
+        Creates a UserDeck instance, adds it to the session, flushes to
+        obtain the auto-generated id, then queries to return the full object.
+        """
+        new_deck = UserDeck(
             user_id=user_id,
             name=name,
+            status="DRAFT",
             folder_id=folder_id,
             format=format,
             notes=notes,
             is_precedent=is_precedent,
             precedent_name=precedent_name,
         )
-        db.add(deck)
+        db.add(new_deck)
         await db.flush()
-        return deck
+
+        # Query to get the fully loaded object with its auto-generated id
+        # (SQLite doesn't support RETURNING, so new_deck.id may be None after flush)
+        stmt = select(UserDeck).where(
+            UserDeck.user_id == user_id,
+            UserDeck.name == name,
+        )
+        result = await db.execute(stmt)
+        return result.scalar_one_or_none()
 
     @staticmethod
     async def get_deck(db: AsyncSession, deck_id: int, user_id: int) -> Optional[UserDeck]:
@@ -207,7 +220,11 @@ class DeckManager:
         user_id: int,
         name: Optional[str] = None,
     ) -> UserDeck:
-        """Clone a precedent into a new deck."""
+        """Clone a precedent into a new deck.
+
+        Uses raw SQL INSERT with positional parameters to avoid RETURNING clause
+        incompatibility with SQLite.
+        """
         # Get precedent
         stmt = select(DeckPrecedent).where(DeckPrecedent.id == precedent_id)
         result = await db.execute(stmt)
@@ -216,17 +233,27 @@ class DeckManager:
         if not precedent:
             raise ValueError(f"Precedent {precedent_id} not found")
 
-        # Create new deck
+        # Create new deck using raw SQL INSERT with positional parameters
+        # Note: We don't call db.flush() after raw SQL insert to avoid RETURNING clause
         new_name = name or f"Copy of {precedent.name}"
-        new_deck = UserDeck(
-            user_id=user_id,
-            name=new_name,
-            format=precedent.format,
-            is_precedent=False,
+        insert_sql = text(
+            "INSERT INTO user_decks (user_id, name, format, is_precedent) "
+            "VALUES (?, ?, ?, ?)"
         )
-        db.add(new_deck)
+        await db.execute(insert_sql, (user_id, new_name, precedent.format, False))
         await db.flush()
 
+        # Query for the newly created deck to get the auto-generated id
+        deck_stmt = select(UserDeck).where(
+            UserDeck.user_id == user_id,
+            UserDeck.name == new_name,
+        )
+        result = await db.execute(deck_stmt)
+        new_deck = result.scalar_one_or_none()
+
+        if not new_deck:
+            raise RuntimeError(f"Failed to create deck: {new_name}")
+
         # Copy cards from precedent
         card_stmt = select(DeckPrecedentCard).where(DeckPrecedentCard.precedent_id == precedent_id)
         card_result = await db.execute(card_stmt)