fix: type mismatch BIGINT->INT4 and FLOAT8->FLOAT4 in traces and faces endpoints

- trace_agent_api: CAST trace_id, frame_number to int; CAST confidence to float4
- identities: CAST frame_number to int; CAST confidence to float4
- Fixes 500 errors on /traces, /trace/:id/faces, /faces/candidates

src/api/trace_agent_api.rs

@@ -89,10 +89,10 @@ async fn list_traces_sorted(
 
     let query = format!(
         "SELECT tt.*, fd.id AS sample_face_id FROM (
-            SELECT trace_id,
+            SELECT trace_id::int AS trace_id,
                    COUNT(*) AS face_count,
-                   MIN(frame_number) AS start_frame,
-                   MAX(frame_number) AS end_frame,
+                   MIN(frame_number)::int AS start_frame,
+                   MAX(frame_number)::int AS end_frame,
                    (MAX(frame_number) - MIN(frame_number))::float8 AS duration_sec,
                    AVG(confidence)::float8 AS avg_confidence
             FROM {}
@@ -248,7 +248,7 @@ async fn list_trace_faces(
         Option<i32>,
         f32,
     )> = sqlx::query_as(
-        &format!("SELECT id, frame_number, x, y, width, height, confidence \
+        &format!("SELECT id, frame_number::int, x, y, width, height, confidence::float4 \
                    FROM {} WHERE file_uuid = $1 AND trace_id = $2 \
                    ORDER BY frame_number ASC LIMIT $3 OFFSET $4",
             crate::core::db::schema::table_name("face_detections"))