feat(i18n): mute + close-to-tray strings

src/lib/i18n/en.json

@@ -376,6 +376,10 @@
   "app.cancel": "Cancel",
   "app.cancel_title": "Discard this recording and delete it",
   "app.recording": "Recording…",
+  "app.mute": "Mute microphone",
+  "app.unmute": "Unmute microphone",
+  "app.mute_title": "Mute microphone (M)",
+  "app.unmute_title": "Unmute microphone (M)",
   "app.backend_title": "Active transcription backend",
   "app.retention_title": "Save audio as .wav for this meeting",
   "app.saving": "saving",
@@ -570,5 +574,7 @@
   "settings.recording.auto_label": "Auto-start recording when a calendar event begins",
   "settings.recording.auto_hint": "Only while WhispAssist is open. When an imported calendar event's start time arrives, a recording begins automatically (using your default retention setting above). Nothing runs in the background — the timer is armed only while the app is running. Import events under Settings → Calendar.",
   "settings.recording.autostart_label": "Launch WhispAssist at login",
-  "settings.recording.autostart_hint": "Starts WhispAssist automatically when you sign in to Windows. Off by default; installs a per-user startup entry (no admin required) and does not begin recording on its own."
+  "settings.recording.autostart_hint": "Starts WhispAssist automatically when you sign in to Windows. Off by default; installs a per-user startup entry (no admin required) and does not begin recording on its own.",
+  "settings.recording.close_tray_label": "Close to system tray",
+  "settings.recording.close_tray_hint": "Closing the window keeps WhispAssist running in the background instead of quitting. Reopen it from the tray icon; use the tray's Quit to exit fully. On by default."
 }