fix: real VU meter levels from pipeline instead of random animation

- Added input_level and output_level to /api/state (scaled 0-100)
- React RigScreen now reads real levels from state instead of random walk
- When no audio flows, VU meters show flat (0) instead of fake animation

src/web/server.py

@@ -1023,6 +1023,8 @@ class WebServer:
                 "nam_model": None,
                 "ir_loaded": False,
                 "ir_name": None,
+                "input_level": 0,
+                "output_level": 0,
                 "wifi": {},
                 "bluetooth": {},
             }
@@ -1065,6 +1067,9 @@ class WebServer:
             "nam_model": current_model_name,
             "ir_loaded": bool(ir and ir.is_loaded) if ir else False,
             "ir_name": current_ir_name,
+            # Audio levels from pipeline (RMS float32 normalized 0.0-1.0, scaled to 0-100)
+            "input_level": min(100, round((pl._input_level or 0.0) * 150)) if pl else 0,
+            "output_level": min(100, round((pl._output_level or 0.0) * 150)) if pl else 0,
             "wifi": self._gather_wifi_state(),
             "bluetooth": self._gather_bt_state(),
         }