Fix: missing timezone import in superadmin grants + naive/aware datetime comparison crash

app/superadmin/router.py

@@ -457,7 +457,7 @@ async def list_all_grants(
         from sqlalchemy import select
         from app.models.client_access import ClientAccess
         from app.models.user import User
-        from datetime import datetime
+        from datetime import datetime, timezone
 
         result = await db.execute(
             select(ClientAccess, User)
@@ -467,17 +467,17 @@ async def list_all_grants(
         )
         rows = result.all()
 
-        now = datetime.now(timezone.utc)  # R-051: timezone-aware UTC
+        now = datetime.now(timezone.utc)
         grants = []
         for access, user in rows:
             total_budget = access.token_budget + access.bonus_tokens
             pct = round((access.tokens_used / total_budget * 100), 1) if total_budget > 0 else 0
             exp = access.expires_at
-            # Strip tz if aware (defensive: handle both naive and aware)
+            # Make both naive for comparison (SQLite stores naive datetimes)
+            now_naive = now.replace(tzinfo=None)
             if exp and exp.tzinfo is not None:
-                from datetime import timezone
                 exp = exp.replace(tzinfo=None)
-            is_expired = exp < now if exp else True
+            is_expired = exp < now_naive if exp else True
             grants.append({
                 "grant_id": access.id,
                 "author_id": access.author_id,
@@ -536,7 +536,7 @@ async def get_author_embed_token(
         from app.models.client_access import ClientAccess
         from app.models.user import User
         from app.core.access.token_crypto import create_subscription_token
-        from datetime import datetime
+        from datetime import datetime, timezone
 
         # Get author info
         user = await db.get(User, author_id)