Switch TTS to edge-tts (ko-KR-SunHiNeural), add TTS toggle + mic auto-send

- Replace piper TTS with edge-tts (Microsoft neural Korean voice)
  - piper ko_KR-kss-medium uses pygoruut phoneme type unsupported by C++ binary,
    causing Chinese-sounding output; edge-tts solves this via online neural TTS
  - Added src/tools/edge_tts_synth.py Python helper script
  - Server TTS endpoint now dispatches by provider (edge_tts vs piper)
  - Config updated: voice.tts.provider = "edge_tts", voice = "ko-KR-SunHiNeural"
- Add TTS toggle switch to web UI (chat input bar)
  - Toggles visibility of all 🔊 buttons and stops active playback
  - State persisted in localStorage (default: on)
- Mic input now auto-submits after speech recognition completes

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web-ui/index.html

@@ -1025,6 +1025,7 @@
   @keyframes mic-pulse { 0%,100%{opacity:1} 50%{opacity:0.55} }
   .tts-btn { background:none;border:none;cursor:pointer;font-size:13px;padding:1px 4px;border-radius:4px;opacity:0.45;vertical-align:middle;line-height:1; }
   .tts-btn:hover,.tts-btn.playing{opacity:1;background:var(--panel-2);}
+  body.tts-disabled .tts-btn { display:none !important; }
   .export-dropdown { position:relative; display:inline-block; }
   .export-menu { display:none; position:absolute; right:0; top:calc(100% + 4px); background:var(--panel-2); border:1px solid var(--border); border-radius:8px; box-shadow:0 4px 16px rgba(0,0,0,0.18); z-index:2000; min-width:160px; overflow:hidden; }
   .export-menu button { display:block; width:100%; padding:8px 14px; text-align:left; background:none; border:none; cursor:pointer; font-size:12px; color:var(--text); white-space:nowrap; }
@@ -2374,6 +2375,12 @@
         </label>
         <span class="agent-toggle-label" id="agent-mode-label">채팅</span>
         <span class="agent-mode-badge" id="agent-mode-badge">AGENT</span>
+        <span style="color:var(--line);margin:0 6px;user-select:none">|</span>
+        <span class="agent-toggle-label">TTS</span>
+        <label class="toggle-switch" title="AI 응답 음성 읽기 켜기/끄기">
+          <input type="checkbox" id="tts-mode-toggle" onchange="updateTTSMode()">
+          <span class="toggle-track"></span>
+        </label>
         <div class="agent-toggle-right" style="display:flex;align-items:center;gap:6px">
           <button class="quick-mode-btn" id="context-pin-btn" onclick="toggleContextPinMode()" title="메시지를 컨텍스트에 고정">
             <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"><path d="M12 17v5"/><path d="M9 10.76a2 2 0 0 1-1.11 1.79l-1.78.9A2 2 0 0 0 5 15.24V16a1 1 0 0 0 1 1h12a1 1 0 0 0 1-1v-.76a2 2 0 0 0-1.11-1.79l-1.78-.9A2 2 0 0 1 15 10.76V7a1 1 0 0 1 1-1 2 2 0 0 0 0-4H8a2 2 0 0 0 0 4 1 1 0 0 1 1 1z"/></svg>
@@ -3946,6 +3953,7 @@ let agentSessionId = '';
 let currentUser = null;
 setAgentSessionId(generateSessionId()); // always fresh session on page load
 checkAuth(); // Check authentication on page load
+initTTSToggle();
 
 // ── Server log panel ──────────────────────────────────────────────────────────
 let logScrollLocked = true;
@@ -8866,6 +8874,7 @@ function startMicRecording() {
       input.value = (input.value ? input.value + ' ' : '') + transcript;
       input.focus();
       input.dispatchEvent(new Event('input'));
+      setTimeout(function() { handleSendStop(); }, 50);
     }
   };
   _speechRecog.onerror = function(e) {
@@ -8884,9 +8893,26 @@ function stopMicRecording() {
 }
 
 // ── Voice: TTS (음성 출력) ───────────────────────────────────────────────
+var _ttsEnabled = localStorage.getItem('ttsEnabled') !== 'false'; // default on
 var _ttsAudio = null;
 var _ttsBtnActive = null;
 
+function updateTTSMode() {
+  _ttsEnabled = document.getElementById('tts-mode-toggle').checked;
+  localStorage.setItem('ttsEnabled', String(_ttsEnabled));
+  document.body.classList.toggle('tts-disabled', !_ttsEnabled);
+  if (!_ttsEnabled && _ttsAudio) {
+    _ttsAudio.pause(); _ttsAudio = null;
+    if (_ttsBtnActive) { _ttsBtnActive.textContent = '🔊'; _ttsBtnActive.classList.remove('playing'); _ttsBtnActive = null; }
+  }
+}
+
+function initTTSToggle() {
+  var toggle = document.getElementById('tts-mode-toggle');
+  if (toggle) toggle.checked = _ttsEnabled;
+  document.body.classList.toggle('tts-disabled', !_ttsEnabled);
+}
+
 function playTTSMsg(btn, idx) {
   var msg = chatHistory[idx];
   if (!msg) return;