S167: always expose engine_log/engine_rc/engine_error/used_fallback

app.py

@@ -372,6 +372,7 @@ def _run_engine(job_id):
         except Exception as exc:
             job["engine_error"] = str(exc)
     if not success:
+        job["used_fallback"] = True
         try:
             job["label"] = "معالجة أساسية (fallback)..."
             job["progress"] = 50
@@ -395,7 +396,8 @@ def _run_engine(job_id):
 
 def _add_history(job):
     entry = {k: job[k] for k in
-             ["engine","filename","score","lufs","rms","crest","lra","timestamp"]
+             ["engine","filename","score","lufs","rms","crest","lra","timestamp",
+              "used_fallback","engine_rc","engine_error","engine_log"]
              if k in job}
     with HISTORY_LOCK:
         HISTORY.insert(0, entry)
@@ -410,9 +412,11 @@ def status(job_id):
             if k in job}
     resp["queue_position"] = _get_queue_position(job_id) if job.get("status") == "queued" else 0
     if "error" in job: resp["error"] = job["error"]
-    if job.get("status") == "error":
-        resp["engine_log"] = job.get("engine_log", [])
-        resp["engine_rc"]  = job.get("engine_rc")
+    # S167: always expose engine diagnostics (incl. fallback runs)
+    resp["engine_log"]    = job.get("engine_log", [])
+    resp["engine_rc"]     = job.get("engine_rc")
+    resp["engine_error"]  = job.get("engine_error")
+    resp["used_fallback"] = job.get("used_fallback", False)
     return jsonify(resp)
 
 @app.route("/download/<job_id>")