feat(voice): "Say <stop-phrase> to end the voice chat" notice on voice-mode start (CLI/TUI/desktop, i18n)

One owner for the wording: voice_stop_hint() in tools/voice_mode.py —
sources the phrase from voice.stop_phrases (first entry) so a custom
phrase renders correctly, and returns "" when the feature is disabled
(stop_phrases: []) so no surface shows a hint.

- CLI: printed in /voice on output (style-matched dim notice).
- TUI: voice.toggle action=on now carries stop_hint; the Ink client
  renders it in the "Voice mode enabled" block (older gateways omit
  the field — no hint, no crash).
- Desktop: the renderer voice loop never touches tools/voice_mode.py,
  so the phrase is read from config (voice.stop_phrases → $voiceStopPhrase
  store, seeded in use-hermes-config) and shown as an info toast when a
  voice conversation starts. i18n: en/ja/zh/zh-hant/ar.

tools/voice_mode.py

@@ -1161,6 +1161,21 @@ def is_voice_stop_phrase(transcript: str, stop_phrases: Optional[tuple] = None)
     return cleaned in stop_phrases
 
 
+def voice_stop_hint() -> str:
+    """One-line 'Say "stop" to end the voice chat.' hint for voice-mode start.
+
+    Sources the phrase from ``voice.stop_phrases`` (first entry) so a custom
+    phrase renders correctly; returns "" when stop phrases are disabled
+    (``stop_phrases: []``) so surfaces show no hint at all. Every surface
+    that announces voice-mode start (CLI /voice on, TUI, desktop) uses this
+    one owner instead of hardcoding the wording.
+    """
+    phrases = _load_voice_stop_phrases()
+    if not phrases:
+        return ""
+    return f'Say "{phrases[0]}" to end the voice chat.'
+
+
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