feat(voice): playback-speed toggle (1x/1.5x/2x) with per-user default

apps/desktop/src/lib/voiceSpeedSettings.ts

@@ -0,0 +1,29 @@
+// Persists the preferred voice-message playback rate across sessions.
+// localStorage is fine here — non-sensitive, single source of truth per
+// device, no cross-device sync needed.
+
+const KEY = 'chatapp:voice-speed';
+const ALLOWED = [1, 1.5, 2] as const;
+export type VoiceSpeed = (typeof ALLOWED)[number];
+
+export function getVoiceSpeed(): VoiceSpeed {
+  try {
+    const raw = window.localStorage.getItem(KEY);
+    if (!raw) return 1;
+    const parsed = Number(raw);
+    if (ALLOWED.includes(parsed as VoiceSpeed)) return parsed as VoiceSpeed;
+  } catch {
+    /* localStorage unavailable */
+  }
+  return 1;
+}
+
+export function setVoiceSpeed(speed: VoiceSpeed): void {
+  try {
+    window.localStorage.setItem(KEY, String(speed));
+  } catch {
+    /* localStorage unavailable — best effort */
+  }
+}
+
+export const VOICE_SPEEDS = ALLOWED;