Keep the Radio tuning dial silent unless a stream is playing

Releasing the tuning dial always started the chosen station, plus tuning
static, even when nothing was playing. It now follows the Previous/Next
rule: the release plays only if a stream was loading, buffering or playing
when the drag began; otherwise it just selects the station.

The privacy note no longer lists finishing tuning as a way to connect and
now names voice instead, in all locales. Docs, changelog and comments are
tightened to match.

src/layers/radio/selection.js

@@ -140,7 +140,7 @@ export function createSelection({
     if (focus) parts.navigation.focusStation(station);
     parts.presentation.emitState();
     if (autoplay) void parts.playback.playSelectedRadio({ origin, attemptId });
-    // A user step to another station overrides a playback voice prepared.
+    // A user step to another station cancels a playback voice prepared.
     else if (origin === 'user' && changed)
       parts.presentation.emitPlaybackControl('select', origin);
     return true;