feat: add require_admin dependency and protect admin endpoints

Add require_admin FastAPI dependency that checks is_admin column on users
table. Apply it to all admin-facing write endpoints (games, pokemon,
evolutions, bosses, routes CRUD). Run-scoped endpoints remain protected
by require_auth only since they manage user's own data.

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

backend/src/app/api/evolutions.py

@@ -3,6 +3,7 @@ from sqlalchemy import func, or_, select
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import joinedload
 
+from app.core.auth import AuthUser, require_admin
 from app.core.database import get_session
 from app.models.evolution import Evolution
 from app.models.pokemon import Pokemon
@@ -89,7 +90,9 @@ async def list_evolutions(
 
 @router.post("/evolutions", response_model=EvolutionAdminResponse, status_code=201)
 async def create_evolution(
-    data: EvolutionCreate, session: AsyncSession = Depends(get_session)
+    data: EvolutionCreate,
+    session: AsyncSession = Depends(get_session),
+    _user: AuthUser = Depends(require_admin),
 ):
     from_pokemon = await session.get(Pokemon, data.from_pokemon_id)
     if from_pokemon is None:
@@ -117,6 +120,7 @@ async def update_evolution(
     evolution_id: int,
     data: EvolutionUpdate,
     session: AsyncSession = Depends(get_session),
+    _user: AuthUser = Depends(require_admin),
 ):
     evolution = await session.get(Evolution, evolution_id)
     if evolution is None:
@@ -150,7 +154,9 @@ async def update_evolution(
 
 @router.delete("/evolutions/{evolution_id}", status_code=204)
 async def delete_evolution(
-    evolution_id: int, session: AsyncSession = Depends(get_session)
+    evolution_id: int,
+    session: AsyncSession = Depends(get_session),
+    _user: AuthUser = Depends(require_admin),
 ):
     evolution = await session.get(Evolution, evolution_id)
     if evolution is None:
@@ -164,6 +170,7 @@ async def delete_evolution(
 async def bulk_import_evolutions(
     items: list[BulkEvolutionItem],
     session: AsyncSession = Depends(get_session),
+    _user: AuthUser = Depends(require_admin),
 ):
     # Build pokeapi_id -> id mapping
     result = await session.execute(select(Pokemon.pokeapi_id, Pokemon.id))