Add drag-and-drop boss reordering and new feature beans

Adds boss battle reorder API endpoint with two-phase order update to
avoid unique constraint violations. Includes frontend mutation hook
and API client. Also adds draft beans for progression dividers and
conditional boss battle teams features.

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

backend/src/app/api/bosses.py

@@ -16,6 +16,7 @@ from app.schemas.boss import (
     BossBattleResponse,
     BossBattleUpdate,
     BossPokemonInput,
+    BossReorderRequest,
     BossResultCreate,
     BossResultResponse,
 )
@@ -50,6 +51,45 @@ async def list_bosses(
     return result.scalars().all()
 
 
+@router.put("/games/{game_id}/bosses/reorder", response_model=list[BossBattleResponse])
+async def reorder_bosses(
+    game_id: int,
+    data: BossReorderRequest,
+    session: AsyncSession = Depends(get_session),
+):
+    vg_id = await _get_version_group_id(session, game_id)
+
+    boss_ids = [item.id for item in data.bosses]
+    result = await session.execute(
+        select(BossBattle).where(
+            BossBattle.id.in_(boss_ids), BossBattle.version_group_id == vg_id
+        )
+    )
+    bosses = {b.id: b for b in result.scalars().all()}
+
+    if len(bosses) != len(boss_ids):
+        raise HTTPException(status_code=400, detail="Some boss IDs not found in this game")
+
+    # Phase 1: set temporary negative orders to avoid unique constraint violations
+    for i, item in enumerate(data.bosses):
+        bosses[item.id].order = -(i + 1)
+    await session.flush()
+
+    # Phase 2: set real orders
+    for item in data.bosses:
+        bosses[item.id].order = item.order
+    await session.commit()
+
+    # Re-fetch with eager loading
+    result = await session.execute(
+        select(BossBattle)
+        .where(BossBattle.version_group_id == vg_id)
+        .options(selectinload(BossBattle.pokemon).selectinload(BossPokemon.pokemon))
+        .order_by(BossBattle.order)
+    )
+    return result.scalars().all()
+
+
 @router.post("/games/{game_id}/bosses", response_model=BossBattleResponse, status_code=201)
 async def create_boss(
     game_id: int,