fix: remove trace_chunks from API + fix OCR frame calculation

- Removed trace_chunks field from PostgresStats struct
- Removed trace_chunks query from get_file_stats and get_ingestion_status
- Fixed OCR fetch_ocr_texts to compute frames from start_time*FPS
- Updated scan.rs to use separate count_nodes/count_edges functions

src/api/scan.rs

@@ -40,7 +40,6 @@ struct ProcessorStatus {
 #[derive(Debug, Serialize, Default)]
 struct PostgresStats {
     sentence_chunks: i64,
-    trace_chunks: i64,
     relationship_chunks: i64,
     identities: i64,
     file_identities: i64,
@@ -514,9 +513,6 @@ async fn get_ingestion_status(
     ));
     let face_total = face_total;
     let trace_count = trace_count;
-    let trace_chunks = count_sql!(&format!(
-        "SELECT COUNT(*) FROM {chunk} WHERE file_uuid = '{file_uuid}' AND chunk_type = 'trace'"
-    ));
     let identity_count = identity_count;
     let tkg_nodes = count_sql!(&format!(
         "SELECT COUNT(*) FROM {} WHERE file_uuid = '{file_uuid}'",
@@ -609,11 +605,6 @@ async fn get_ingestion_status(
             trace_count > 0,
             Some(format!("{trace_count} traces / {face_total} detections"))
         ),
-        step!(
-            "trace_chunks",
-            trace_chunks > 0,
-            Some(format!("{trace_chunks} trace chunks"))
-        ),
         // TKG Nodes
         step!("tkg_face_track", face_track_nodes > 0, Some(format!("{face_track_nodes} nodes"))),
         step!("tkg_gaze_track", gaze_track_nodes > 0, Some(format!("{gaze_track_nodes} nodes"))),
@@ -736,13 +727,6 @@ async fn get_file_stats(
         .fetch_one(pool)
         .await
         .unwrap_or(0),
-        trace_chunks: sqlx::query_scalar::<_, i64>(&format!(
-            "SELECT COUNT(*) FROM {chunk_table} WHERE file_uuid = $1 AND chunk_type = 'trace'"
-        ))
-        .bind(&file_uuid)
-        .fetch_one(pool)
-        .await
-        .unwrap_or(0),
         relationship_chunks: sqlx::query_scalar::<_, i64>(&format!(
             "SELECT COUNT(*) FROM {chunk_table} WHERE file_uuid = $1 AND chunk_type = 'relationship'"
         ))