feat: trace chunks with co-appearance relationships

- New trace_ingest module: creates chunks for each face trace (time + bbox + ASR text)
- Computes pairwise time overlaps between traces -> co_appearances in metadata
- Worker auto-triggers after face trace store + Qdrant sync
- SearchFilters: chunk_type filter (sentence/cut/trace/visual)
- SearchFilters: co_appears_with_trace_id filter

src/worker/job_worker.rs

@@ -713,6 +713,7 @@ impl JobWorker {
             // Runs face_tracker.py (IoU+embedding tracking), stores trace_id + position in DB
             if has_face {
                 info!("📝 Face completed, triggering face trace + DB store...");
+                let db_clone = self.db.clone();
                 let uuid_clone = uuid.to_string();
                 tokio::spawn(async move {
                     let executor = match crate::core::processor::PythonExecutor::new() {
@@ -744,6 +745,18 @@ impl JobWorker {
                             } else {
                                 info!("✅ Qdrant face sync completed for {}", uuid_clone);
                             }
+
+                            // Generate trace chunks from face_detections + ASR text
+                            info!("📝 Generating trace chunks...");
+                            match crate::core::chunk::trace_ingest::ingest_traces(
+                                &db_clone,
+                                &uuid_clone,
+                            )
+                            .await
+                            {
+                                Ok(n) => info!("✅ {} trace chunks created for {}", n, uuid_clone),
+                                Err(e) => error!("❌ Trace chunk ingestion failed: {}", e),
+                            }
                         }
                         Err(e) => {
                             error!("❌ Face trace + DB store failed for {}: {}", uuid_clone, e)