Fix /control/trackers: use TrackerDispatcher.read_current_angles()

backend/api/routes/control.py

@@ -64,10 +64,11 @@ async def control_budget():
 @router.get("/trackers")
 async def control_trackers():
     """Live tracker angles from ThingsBoard."""
-    hub = get_datahub()
     try:
-        snapshot = hub.vine_sensors.get_snapshot(light=True)
-        return {"trackers": snapshot.get("trackers", {}), "source": "ThingsBoard"}
+        from src.tracker_dispatcher import TrackerDispatcher
+        dispatcher = TrackerDispatcher()
+        angles = dispatcher.read_current_angles()
+        return {"trackers": angles, "source": "ThingsBoard"}
     except Exception as exc:
         log.error("Tracker fetch failed: %s", exc)
-        raise HTTPException(status_code=502, detail="Tracker fetch failed")
+        raise HTTPException(status_code=502, detail=f"Tracker fetch failed: {exc}")