G3: 1 clock - PDC latency that + playhead engine-derived

app/api/v1/plugins.py

@@ -1134,18 +1134,27 @@ async def ws_fx_realtime(websocket: WebSocket, session_id: str):
         if _pf is not None:
             _pf.write("%d pump_start\n" % int(_time.time() * 1000))
         _last_lat = None
+        _last_proc = None
         try:
             while True:
                 try:
                     sess.flush_input_stale()  # input lẻ kẹt trong pending → publish
                     _lats = sess.get_latencies()
                     _total = sum(_lats.values()) if _lats else 0
-                    if _total != _last_lat:
+                    # G3: processed samples (playhead engine-derived) — bridge
+                    # bao moi block; gui kem latency message khi doi (khong gate
+                    # theo total nua — total chi doi khi chain doi, processed
+                    # doi lien tuc). App: position = (processed - anchor - lat)/sr.
+                    _proc = sess.get_processed()
+                    _proc_changed = (_proc is not None and _proc != _last_proc)
+                    if _total != _last_lat or _proc_changed:
                         _last_lat = _total
+                        _last_proc = _proc
                         await websocket.send_text(json.dumps({
                             "cmd": "latency",
                             "total": _total,
                             "latencies": _lats,
+                            "processed": _proc,
                             "stats": sess.stats,
                         }))
                 except Exception: