Bring back the tuner-release and connecting-label Radio fixes

Restore the two fixes the previous commit moved out:

- A tuner release onto a station the directory dropped mid-drag stops the
  stream the drag paused, publishing one state with the gesture's origin,
  so the button reads PLAY and a voice handoff is cancelled.
- The transport buttons offer Pause while a stream connects, matching
  what a click does.

Their tests now use the shared Radio layer harness.

src/ui/radioPresentation.js

@@ -20,7 +20,9 @@ export function renderRadioState(state) {
   const interactive = enabled && !transitioning && !uncertain;
   const selected = state.selected || null;
   const hasStations = state.filteredCount > 0;
-  const activePlayback = ['playing', 'buffering'].includes(state.audioState);
+  const activePlayback = ['loading', 'buffering', 'playing'].includes(
+    state.audioState,
+  );
   document
     .getElementById('title-bar')
     ?.classList.toggle('radio-broadcasting', state.audioState === 'playing');