fix(spectrum): reset analyser on station change and retry SYNC

somafm_tui/app.py

@@ -324,6 +324,9 @@ class SomaFMApp(App[None]):
             self._set_notice("audio disabled (--no-audio)", 5)
             return
 
+        # A tune gets a clean analyser: forget any previous capture failure and
+        # clear the old station's bars before the new stream starts.
+        self.spectrum.reset()
         self._resolve_and_play(station.id)
         self._fetch_history(station.id)