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/api/universal_search.rs

@@ -273,7 +273,7 @@ pub struct FrameResult {
 
 #[derive(Debug, Deserialize)]
 pub struct PersonSearchQuery {
-    pub video_uuid: String,
+    pub file_uuid: String,
     pub query: Option<String>,
     pub min_appearances: Option<i32>,
     pub max_age: Option<i32>, // New filter for "children"