feat(health): expand path recovery to include broken staging paths

[drondeseries]

This PR further improves the automated health path recovery:

• Enhanced Recovery: The system now identifies not just NULL paths, but also existing paths that point to the '/complete/' directory but no longer exist on disk.
• Auto-Healing: During Library Sync, it will automatically attempt to find these files at their expected library location and update the database.
• Robustness: Ensures that legacy records from before the move tracking was implemented are correctly re-linked.