feat: update core API, database layer, and worker modules

- Remove unused imports (n8n_search, universal_search, Client, Arc, etc.)
- Update API endpoints for identity, face recognition, search
- Fix postgres_db.rs search_videos parent_uuid column
- Add snapshot API and identity agent API
- Clean up backup files (.bak, .bak2)

src/cli/mod.rs

@@ -0,0 +1,5 @@
+//! CLI command definitions and argument parsing
+
+pub mod args;
+
+pub use args::*;