feat: Bug-Runde + 5 App/Diagnostic-Features

Bugs:
- App Mute-/Auto-Playback: onMessage-Closure hielt stale ttsDeviceEnabled/
  ttsMuted → Mute wurde ignoriert + AsyncStorage-Load kam nicht durch.
  Fix via ttsCanPlayRef (live gespiegelt) statt Closure-Variablen.
- App Zombie-Recording: toggleWakeWord hat die laufende Aufnahme nicht
  gestoppt → audioService.recordingState blieb 'recording' → normaler
  Aufnahme-Button wirkungslos. Fix: await stopRecording() vor stop().
- Porcupine robuster: BuiltInKeywords-Enum Mapping mit String-Fallback,
  errorCallback fuer Runtime-Crashes (state zurueck auf off statt
  App-Crash), mehr Logging damit man beim naechsten Issue debuggen kann.

App-Features:
- MessageText Komponente: Text ist durchgehend selektierbar, erkennt
  URLs (http/https), E-Mails, Telefonnummern und macht sie anklickbar
  (oeffnet Browser / Mail-App / Android-Dialer via Linking).
- TTS-Wiedergabegeschwindigkeit pro Geraet einstellbar (Settings ->
  "Sprechgeschwindigkeit", 0.5-2.0 in 0.1-Schritten, Default 1.0).
  Wird als speed-Param an die F5-TTS-Bridge durchgereicht.

Bridge-Durchreichen:
- ChatScreen: speed aus AsyncStorage via ttsSpeedRef, an chat/audio/
  tts_request mitgeschickt
- aria-bridge: _next_speed_override wie voice_override, an xtts_request
  weitergereicht
- f5tts-bridge: speed-Param an F5TTS.infer() durchgereicht

Diagnostic-Feature:
- Voice-Preview-Button (Play-Icon) vor dem Delete-X in der Stimmen-Liste
- Modal mit Textfeld (Default-Beispieltext wird bei jedem Oeffnen neu
  gesetzt) und Play-Button
- Server sammelt audio_pcm Frames der Preview-Anfrage, baut WAV,
  schickt base64 zurueck, Browser spielt im <audio>-Tag ab
- 60s Timeout-Safety-Net

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

diagnostic/index.html

@@ -136,6 +136,25 @@
     </div>
   </div>
 
+  <!-- Voice-Preview Modal -->
+  <div id="voice-preview-modal" style="display:none;position:fixed;inset:0;z-index:1000;background:rgba(0,0,0,0.7);align-items:center;justify-content:center;">
+    <div style="background:#1A1A2E;border:1px solid #2A2A3E;border-radius:10px;padding:20px;max-width:560px;width:90%;display:flex;flex-direction:column;gap:12px;">
+      <div style="display:flex;align-items:center;justify-content:space-between;">
+        <h3 style="margin:0;color:#fff;">Stimmen-Preview: <span id="voice-preview-name">—</span></h3>
+        <button onclick="closeVoicePreview()" style="background:none;border:none;color:#8888AA;font-size:22px;cursor:pointer;">&times;</button>
+      </div>
+      <textarea id="voice-preview-text" rows="4"
+        style="background:#0D0D1A;border:1px solid #2A2A3E;border-radius:6px;padding:10px;color:#fff;font-size:13px;resize:vertical;"></textarea>
+      <div style="display:flex;gap:8px;align-items:center;">
+        <button id="voice-preview-play" onclick="playVoicePreview()" class="btn primary" style="padding:8px 16px;">
+          ▶ Abspielen
+        </button>
+        <span id="voice-preview-status" style="color:#8888AA;font-size:11px;flex:1;"></span>
+      </div>
+      <audio id="voice-preview-audio" controls style="width:100%;display:none;"></audio>
+    </div>
+  </div>
+
   <!-- Disk-Space Warnung (dynamisch gesetzt) -->
   <div id="disk-banner" style="display:none;position:sticky;top:0;z-index:500;padding:10px 14px;border-radius:0;margin:-16px -16px 12px -16px;font-size:13px;">
     <div style="display:flex;align-items:center;gap:10px;flex-wrap:wrap;">
@@ -930,6 +949,24 @@
           return;
         }
 
+        if (msg.type === 'voice_preview_audio') {
+          const statusEl = document.getElementById('voice-preview-status');
+          const audio = document.getElementById('voice-preview-audio');
+          const playBtn = document.getElementById('voice-preview-play');
+          if (playBtn) playBtn.disabled = false;
+          if (msg.error) {
+            if (statusEl) statusEl.textContent = '❌ Fehler: ' + msg.error;
+            return;
+          }
+          if (msg.base64 && audio) {
+            audio.src = 'data:audio/wav;base64,' + msg.base64;
+            audio.style.display = 'block';
+            audio.play().catch(() => {});
+            if (statusEl) statusEl.textContent = '✅ fertig';
+          }
+          return;
+        }
+
         if (msg.type === 'voice_ready') {
           const v = msg.payload?.voice || '';
           const err = msg.payload?.error;
@@ -1579,16 +1616,51 @@
       html += '<div style="display:flex;flex-direction:column;gap:4px;">';
       for (const v of voices) {
         const esc = (s) => String(s).replace(/[&<>"']/g, c => ({ "&":"&amp;", "<":"&lt;", ">":"&gt;", '"':"&quot;", "'":"&#39;" }[c]));
+        const jsName = esc(v.name).replace(/'/g, "\\'");
         html += `<div style="display:flex;align-items:center;gap:8px;background:#1E1E2E;border-radius:4px;padding:4px 8px;font-size:12px;">`
               + `<span style="flex:1;color:#E0E0F0;">${esc(v.name)}</span>`
               + `<span style="color:#555570;font-size:10px;">${(v.size/1024).toFixed(0)}KB</span>`
-              + `<button class="btn secondary" onclick="deleteXttsVoice('${esc(v.name).replace(/'/g, "\\'")}')" style="padding:2px 8px;font-size:10px;color:#FF6B6B;" title="Stimme loeschen">X</button>`
+              + `<button class="btn secondary" onclick="openVoicePreview('${jsName}')" style="padding:2px 8px;font-size:12px;" title="Stimme anhoeren">▶</button>`
+              + `<button class="btn secondary" onclick="deleteXttsVoice('${jsName}')" style="padding:2px 8px;font-size:10px;color:#FF6B6B;" title="Stimme loeschen">X</button>`
               + `</div>`;
       }
       html += '</div>';
       box.innerHTML = html;
     }
 
+    // ── Voice Preview Modal ─────────────────────────
+    const VOICE_PREVIEW_DEFAULT = 'Hallo, ich bin ARIA. Das hier ist ein kleiner Test damit du meine Stimme beurteilen kannst.';
+    let currentPreviewVoice = '';
+
+    function openVoicePreview(name) {
+      currentPreviewVoice = name;
+      document.getElementById('voice-preview-name').textContent = name;
+      // Text bei jedem Oeffnen zuruecksetzen
+      document.getElementById('voice-preview-text').value = VOICE_PREVIEW_DEFAULT;
+      document.getElementById('voice-preview-status').textContent = '';
+      const audio = document.getElementById('voice-preview-audio');
+      audio.style.display = 'none';
+      audio.src = '';
+      document.getElementById('voice-preview-modal').style.display = 'flex';
+    }
+
+    function closeVoicePreview() {
+      document.getElementById('voice-preview-modal').style.display = 'none';
+      const audio = document.getElementById('voice-preview-audio');
+      try { audio.pause(); } catch {}
+    }
+
+    function playVoicePreview() {
+      const text = (document.getElementById('voice-preview-text').value || '').trim();
+      if (!text) {
+        document.getElementById('voice-preview-status').textContent = 'Text leer';
+        return;
+      }
+      document.getElementById('voice-preview-status').textContent = '⏳ Rendere...';
+      document.getElementById('voice-preview-play').disabled = true;
+      send({ action: 'preview_voice', voice: currentPreviewVoice, text });
+    }
+
     function deleteXttsVoice(name) {
       if (!confirm(`Stimme "${name}" endgueltig loeschen?`)) return;
       send({ action: 'xtts_delete_voice', name });