Fix dev tier: default to power when no subscription exists

The tier is resolved live from the subscriptions table in get_current_user.
Previously fell back to 'free' unconditionally, hitting the 5 runs/day
limit immediately in dev. Now falls back to 'power' (unlimited) when
ENV=dev and no subscription row exists.

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

app/api/middleware/auth.py

@@ -55,12 +55,15 @@ async def get_current_user(
         raise credentials_exc
 
     # Live tier lookup — subscription row is the authoritative source.
+    # In dev, fall back to 'power' (unlimited) so quota limits don't
+    # block local development when no Stripe subscription exists.
     from app.models import Subscription, User  # noqa: PLC0415
 
     result = await db.execute(
         select(Subscription.tier).where(Subscription.user_id == user_id)
     )
-    tier: str = result.scalar_one_or_none() or "free"
+    default_tier = "power" if settings.ENV == "dev" else "free"
+    tier: str = result.scalar_one_or_none() or default_tier
 
     # Fetch name/surname from user row.
     user_result = await db.execute(