test(tasks): add comprehensive tests for per-user cloud scan functions and gmail_apply_labels

Add 68 new unit tests covering:
- _scan_user_s3_folder: 10 tests (bucket config, credentials, client creation,
  pagination, download, cache, file types, delete, error handling)
- _scan_user_dropbox_folder: 9 tests (credentials, folder path, auth, listing,
  download, cache, non-file entries, delete, download failure)
- _scan_user_google_drive_folder: 8 tests (credentials JSON, folder ID, auth,
  download, cache, delete, download/listing failures)
- _scan_user_onedrive_folder: 10 tests (credentials, folder path, token exchange,
  download, folders, cache, download URL, delete, download/listing failures)
- _scan_user_nextcloud_folder: 9 tests (settings, PROPFIND, XML parse, download,
  self-entry, cache, delete, download failure, absolute href)
- _scan_user_webdav_folder: 9 tests (URL config, PROPFIND, XML parse, download,
  directories, cache, delete, download failure, absolute href)
- Dispatch tests for google_drive, onedrive, nextcloud, webdav source types
- gmail_apply_labels forwarding and default-to-true in IMAP integration

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

tests/test_imap_tasks.py

@@ -1584,6 +1584,55 @@ class TestPullUserIntegrationImap:
         assert mock_integ.last_error is None
         assert mock_integ.last_used_at is not None
 
+    @patch("app.tasks.imap_tasks._get_db_session")
+    @patch("app.tasks.imap_tasks.pull_inbox")
+    def test_passes_gmail_apply_labels_config_to_pull_inbox(self, mock_pull, mock_session_factory):
+        """gmail_apply_labels config should be forwarded to pull_inbox."""
+        from app.tasks.imap_tasks import _pull_user_integration_imap
+
+        mock_integ = MagicMock()
+        mock_integ.id = 14
+        mock_integ.owner_id = "owner-gmail"
+        mock_integ.config = (
+            '{"host": "imap.gmail.com", "port": 993, "username": "u@gmail.com",'
+            ' "use_ssl": true, "gmail_apply_labels": false}'
+        )
+        mock_integ.credentials = "enc:encrypted"
+
+        mock_db = MagicMock()
+        mock_db.query.return_value.filter.return_value.all.return_value = [mock_integ]
+        mock_session_factory.return_value = mock_db
+
+        with patch("app.utils.encryption.decrypt_value", return_value='{"password": "p"}'):
+            _pull_user_integration_imap()
+
+        mock_pull.assert_called_once()
+        call_kwargs = mock_pull.call_args
+        assert call_kwargs.kwargs.get("gmail_apply_labels") is False
+
+    @patch("app.tasks.imap_tasks._get_db_session")
+    @patch("app.tasks.imap_tasks.pull_inbox")
+    def test_gmail_apply_labels_defaults_to_true(self, mock_pull, mock_session_factory):
+        """Config without gmail_apply_labels should default to True."""
+        from app.tasks.imap_tasks import _pull_user_integration_imap
+
+        mock_integ = MagicMock()
+        mock_integ.id = 15
+        mock_integ.owner_id = "owner-gmail2"
+        mock_integ.config = '{"host": "imap.gmail.com", "port": 993, "username": "u@gmail.com", "use_ssl": true}'
+        mock_integ.credentials = "enc:encrypted"
+
+        mock_db = MagicMock()
+        mock_db.query.return_value.filter.return_value.all.return_value = [mock_integ]
+        mock_session_factory.return_value = mock_db
+
+        with patch("app.utils.encryption.decrypt_value", return_value='{"password": "p"}'):
+            _pull_user_integration_imap()
+
+        mock_pull.assert_called_once()
+        call_kwargs = mock_pull.call_args
+        assert call_kwargs.kwargs.get("gmail_apply_labels") is True
+
 
 @pytest.mark.unit
 class TestPullAllInboxesCallsIntegrations: