fix: API endpoints for file_uuid filtering of pending identities

- get_file_identities: UNION face_detections + file_identities
- list_identities: add file_bindings from file_identities table
- Add back /api/v1/traces/unassigned route
- Total count query now includes file_identities

Frontend can now:
- Filter pending identities by file_uuid
- Filter pending faces (unassigned traces) by file_uuid

src/api/identity_api.rs

@@ -266,10 +266,16 @@ async fn get_file_identities(
         })
         .collect();
 
+    let fi_table = crate::core::db::schema::table_name("file_identities");
     let total = match sqlx::query_scalar::<_, i64>(
         &format!(
-            "SELECT COUNT(DISTINCT fd.identity_id) FROM {} fd WHERE fd.file_uuid = $1 AND fd.identity_id IS NOT NULL",
-            crate::core::db::schema::table_name("face_detections")
+            r#"SELECT COUNT(DISTINCT identity_id) FROM (
+                SELECT identity_id FROM {} WHERE file_uuid = $1 AND identity_id IS NOT NULL
+                UNION
+                SELECT identity_id FROM {} WHERE file_uuid = $1
+            ) combined"#,
+            crate::core::db::schema::table_name("face_detections"),
+            fi_table
         )
     )
     .bind(&file_uuid)