Fix calls to private connect/disconnect methods

Change remaining .connect() and .disconnect() calls to private
._connect() and ._disconnect() after removing public methods.

Changes:
- Update EmailForwarder.sync_all_folders to use _connect/_disconnect

email_forwarder/email_forwarder.py

@@ -165,8 +165,8 @@ class EmailForwarder:
 
     def sync_all_folders(self):
         """Sync all configured folders."""
-        self.source.connect()
-        self.dest.connect()
+        self.source._connect()
+        self.dest._connect()
 
         folders_config = self.config["folders"]
         folders = self.source.get_folders_to_sync(folders_config)
@@ -185,8 +185,8 @@ class EmailForwarder:
             except Exception as e:
                 logging.error(f"Error syncing {folder}: {e}")
 
-        self.source.disconnect()
-        self.dest.disconnect()
+        self.source._disconnect()
+        self.dest._disconnect()
         logging.info(f"Total forwarded: {total_forwarded}")
 
     def sync_folder(self, folder: str, uids: list):