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;

src/layers/radio/state.js

@@ -78,6 +78,8 @@ export function createState({ services }) {
 
   layerState._tuningStartStationId = null;
 
+  layerState._tuningResumesPlayback = false;
+
   layerState._tuningResolutionSnapshot = EMPTY_ACCEPTED_CATALOG_SNAPSHOT;
 
   layerState._tuningStationById = new Map();

src/layers/radio/tuning.js

@@ -66,6 +66,12 @@ export function createTuning({ state: layerState, services, parts, source }) {
     layerState._cancelledTuningPresentationStation = null;
     layerState._tuningStartStationId = layerState._selectedId;
     layerState._tuningPreviewId = layerState._selectedId;
+    // Like Previous/Next, the release plays only if a stream was active.
+    layerState._tuningResumesPlayback = [
+      'loading',
+      'buffering',
+      'playing',
+    ].includes(layerState._audioState);
     parts.tuningNoise.installTuningNoise();
     parts.playback.pauseRadioPlayback({ origin: 'user' });
     parts.tuningNoise.syncTuningNoiseGain();
@@ -179,9 +185,8 @@ export function createTuning({ state: layerState, services, parts, source }) {
       layerState._selectionGeneration += 1;
       parts.tuningNoise.clearRadioTuningNoise({ emit: false });
       layerState._tuningUnavailableStationId = stationId;
-      // The drag paused the previous stream; with no selection left, Resume
-      // could only start the nearest station, so release it. Stop publishes
-      // the state, and as the user's gesture it cancels a voice handoff.
+      // The drag paused the stream; with no selection, Resume would start the
+      // nearest station. Stop also publishes the state and cancels a voice handoff.
       parts.playback.stopRadioPlayback({ origin });
       return Object.freeze({
         ok: false,
@@ -190,9 +195,11 @@ export function createTuning({ state: layerState, services, parts, source }) {
         generation,
       });
     }
+    const autoplay = layerState._tuningResumesPlayback;
+    layerState._tuningResumesPlayback = false;
     layerState._tuningActive = false;
-    layerState._tuningStatic = true;
-    layerState._tuningAwaitingStationId = frozenStation.id;
+    layerState._tuningStatic = autoplay;
+    layerState._tuningAwaitingStationId = autoplay ? frozenStation.id : null;
     layerState._tuningPreviewId = null;
     layerState._tuningStartStationId = null;
     layerState._tuningUnavailableStationId = null;
@@ -210,7 +217,7 @@ export function createTuning({ state: layerState, services, parts, source }) {
     parts.tuningNoise.syncTuningNoiseGain();
     parts.presentation.emitState();
     const selected = parts.selection.selectRadioStation(frozenStation.id, {
-      autoplay: true,
+      autoplay,
       focus: false,
       origin,
       cameraNavigation,