fix(librarian): register JanitorCleanupFavoritesTask in scribe priority (#768)

JanitorCleanupFavoritesTask was wired into janitor dispatch, nightly
queueing, and the admin task map, but missing from _SCRIBE_TASK_PRIORITY.
When the task hit the scribe queue, tuple.index() raised ValueError, the
put silently failed, and "Cleanup Orphans Favorites" stayed pending
forever.

Add it to the priority tuple and align Bookmarks/Settings ordering with
_NIGHTLY_TASK_CLASSES so the two tuples stay in sync.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ajslater

codex/librarian/scribe/priority.py

@@ -11,6 +11,7 @@
     JanitorCleanCoversTask,
     JanitorCleanFKsTask,
     JanitorCleanupBookmarksTask,
+    JanitorCleanupFavoritesTask,
     JanitorCleanupSessionsTask,
     JanitorCleanupSettingsTask,
     JanitorCodexUpdateTask,
@@ -55,8 +56,9 @@
     JanitorCleanFKsTask,
     JanitorCleanCoversTask,
     JanitorCleanupSessionsTask,
-    JanitorCleanupSettingsTask,
     JanitorCleanupBookmarksTask,
+    JanitorCleanupSettingsTask,
+    JanitorCleanupFavoritesTask,
     SearchIndexClearTask,
     SearchIndexCleanStaleTask,
     SearchIndexSyncTask,