Fix IMAP provider imports - use Message instead of email.message.Message to avoid conflict with Email model

src/email_providers/imap.py

@@ -6,7 +6,8 @@ STUB STATUS: Requires IMAP server credentials
 - When credentials missing: Provider will fail gracefully
 """
 import logging
-import email
+from email import message_from_bytes
+from email.message import Message
 from typing import List, Dict, Optional, Any
 from datetime import datetime
 from email.utils import parsedate_to_datetime
@@ -138,7 +139,7 @@ class IMAPProvider(BaseProvider):
             logger.error(f"IMAP FETCH ERROR: {e}")
             return emails
 
-    def _parse_message(self, msg: email.message.Message, msg_id: int) -> Optional[Email]:
+    def _parse_message(self, msg: Message, msg_id: int) -> Optional[Email]:
         """Parse email.message.Message into Email object."""
         try:
             subject = msg.get('subject', 'No Subject')