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/core/probe/ffprobe.rs

@@ -16,6 +16,7 @@ pub struct StreamInfo {
     pub width: Option<u32>,
     pub height: Option<u32>,
     pub r_frame_rate: Option<String>,
+    pub nb_frames: Option<String>,
     pub duration: Option<String>,
     pub sample_rate: Option<String>,
     pub channels: Option<u32>,
@@ -64,6 +65,7 @@ pub fn probe_video(video_path: &str) -> Result<ProbeResult> {
                     width: s["width"].as_u64().map(|v| v as u32),
                     height: s["height"].as_u64().map(|v| v as u32),
                     r_frame_rate: s["r_frame_rate"].as_str().map(String::from),
+                    nb_frames: s["nb_frames"].as_str().map(String::from),
                     duration: s["duration"].as_str().map(String::from),
                     sample_rate: s["sample_rate"].as_str().map(String::from),
                     channels: s["channels"].as_u64().map(|v| v as u32),