```

Rename metadata fields for clarity and fix imports.

Updated metadata-related field names across models to improve clarity and consistency (e.g., `metadata` to `media_metadata` and `notification_metadata`). Fixed an error in `guest_gifts` metadata reference and added a proper imports initialization in `__init__.py` for all models.
```

backend/app/models/notification_log.py

@@ -1,7 +1,7 @@
 from datetime import datetime, timezone
 from enum import Enum
 
-from sqlalchemy import Column, String, ForeignKey, Enum as SQLEnum, Text, DateTime
+from sqlalchemy import Column, String, ForeignKey, Enum as SQLEnum, Text, DateTime, Integer
 from sqlalchemy.dialects.postgresql import UUID, JSONB
 from sqlalchemy.orm import relationship
 
@@ -50,7 +50,7 @@ class NotificationLog(Base, UUIDMixin, TimestampMixin):
     external_id = Column(String)  # ID from external provider (SendGrid, Twilio, etc.)
 
     # Additional Data
-    metadata = Column(JSONB, default=dict)
+    notification_metadata = Column(JSONB, default=dict)
 
     # Relationships
     event = relationship("Event")