Backend enhancements: auth, channels, restaurants, daemon improvements

- Add admin auth dependency and role checks
- Expand channel and restaurant API routes
- Improve YouTube transcript fetching
- Enhance daemon worker with better error handling and scheduling

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

backend/core/auth.py

@@ -67,6 +67,9 @@ def find_or_create_user(
                 "email": email, "nickname": nickname,
                 "avatar_url": avatar_url, "id": row[0],
             })
+            # Fetch is_admin
+            cur.execute("SELECT is_admin FROM tasteby_users WHERE id = :id", {"id": row[0]})
+            is_admin = bool(cur.fetchone()[0])
             return {
                 "id": row[0],
                 "provider": row[1],
@@ -74,6 +77,7 @@ def find_or_create_user(
                 "email": email or row[3],
                 "nickname": nickname or row[4],
                 "avatar_url": avatar_url or row[5],
+                "is_admin": is_admin,
             }
 
         # Create new user
@@ -99,6 +103,7 @@ def find_or_create_user(
             "email": email,
             "nickname": nickname,
             "avatar_url": avatar_url,
+            "is_admin": False,
         }
 
 
@@ -108,6 +113,7 @@ def create_jwt(user: dict) -> str:
         "sub": user["id"],
         "email": user.get("email"),
         "nickname": user.get("nickname"),
+        "is_admin": user.get("is_admin", False),
         "exp": datetime.now(timezone.utc) + timedelta(days=JWT_EXPIRE_DAYS),
         "iat": datetime.now(timezone.utc),
     }