Add version groups to share routes and boss battles across games

Routes and boss battles now belong to a version_group instead of
individual games, so paired versions (e.g. Red/Blue, Gold/Silver)
share the same route structure and boss battles. Route encounters
gain a game_id column to support game-specific encounter tables
within a shared route. Includes migration, updated seeds, API
changes, and frontend type updates.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/app/api/bosses.py

@@ -23,6 +23,15 @@ from app.schemas.boss import (
 router = APIRouter()
 
 
+async def _get_version_group_id(session: AsyncSession, game_id: int) -> int:
+    game = await session.get(Game, game_id)
+    if game is None:
+        raise HTTPException(status_code=404, detail="Game not found")
+    if game.version_group_id is None:
+        raise HTTPException(status_code=400, detail="Game has no version group assigned")
+    return game.version_group_id
+
+
 # --- Game-scoped (admin) endpoints ---
 
 
@@ -30,13 +39,11 @@ router = APIRouter()
 async def list_bosses(
     game_id: int, session: AsyncSession = Depends(get_session)
 ):
-    game = await session.get(Game, game_id)
-    if game is None:
-        raise HTTPException(status_code=404, detail="Game not found")
+    vg_id = await _get_version_group_id(session, game_id)
 
     result = await session.execute(
         select(BossBattle)
-        .where(BossBattle.game_id == game_id)
+        .where(BossBattle.version_group_id == vg_id)
         .options(selectinload(BossBattle.pokemon).selectinload(BossPokemon.pokemon))
         .order_by(BossBattle.order)
     )
@@ -49,11 +56,9 @@ async def create_boss(
     data: BossBattleCreate,
     session: AsyncSession = Depends(get_session),
 ):
-    game = await session.get(Game, game_id)
-    if game is None:
-        raise HTTPException(status_code=404, detail="Game not found")
+    vg_id = await _get_version_group_id(session, game_id)
 
-    boss = BossBattle(game_id=game_id, **data.model_dump())
+    boss = BossBattle(version_group_id=vg_id, **data.model_dump())
     session.add(boss)
     await session.commit()
 
@@ -73,9 +78,11 @@ async def update_boss(
     data: BossBattleUpdate,
     session: AsyncSession = Depends(get_session),
 ):
+    vg_id = await _get_version_group_id(session, game_id)
+
     result = await session.execute(
         select(BossBattle)
-        .where(BossBattle.id == boss_id, BossBattle.game_id == game_id)
+        .where(BossBattle.id == boss_id, BossBattle.version_group_id == vg_id)
         .options(selectinload(BossBattle.pokemon).selectinload(BossPokemon.pokemon))
     )
     boss = result.scalar_one_or_none()
@@ -103,8 +110,10 @@ async def delete_boss(
     boss_id: int,
     session: AsyncSession = Depends(get_session),
 ):
+    vg_id = await _get_version_group_id(session, game_id)
+
     result = await session.execute(
-        select(BossBattle).where(BossBattle.id == boss_id, BossBattle.game_id == game_id)
+        select(BossBattle).where(BossBattle.id == boss_id, BossBattle.version_group_id == vg_id)
     )
     boss = result.scalar_one_or_none()
     if boss is None:
@@ -125,9 +134,11 @@ async def set_boss_team(
     team: list[BossPokemonInput],
     session: AsyncSession = Depends(get_session),
 ):
+    vg_id = await _get_version_group_id(session, game_id)
+
     result = await session.execute(
         select(BossBattle)
-        .where(BossBattle.id == boss_id, BossBattle.game_id == game_id)
+        .where(BossBattle.id == boss_id, BossBattle.version_group_id == vg_id)
         .options(selectinload(BossBattle.pokemon))
     )
     boss = result.scalar_one_or_none()