GUI: Record-Button in Kopfzeile (Aufnahme-Tab entfernt) + Live-Karte; lame-Stille-Fix

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0113vDKdSNtD3Dwcw4QMu9yV

app/recorder.js

@@ -308,9 +308,18 @@ export async function stopAndSave() {
   const mp3Path = path.join(REC_DIR, `${base}.mp3`);
   // Gentle cleanup for playback: cut low rumble + normalize loudness. Applied to
   // the MP3 only; whisper still transcribes the untouched WAV.
-  await pexec('ffmpeg', ['-y', '-i', c.wavPath,
-    '-af', 'highpass=f=80,loudnorm=I=-16:TP=-1.5:LRA=11',
-    '-codec:a', 'libmp3lame', '-qscale:a', '3', mp3Path]);
+  // lame's psymodel asserts (`calc_energy: el >= 0`) on pure digital silence —
+  // real since the gated mic path: nobody spoke = all-zero samples. Fall back
+  // to a filterless encode instead of failing the whole stop.
+  try {
+    await pexec('ffmpeg', ['-y', '-i', c.wavPath,
+      '-af', 'highpass=f=80,loudnorm=I=-16:TP=-1.5:LRA=11',
+      '-codec:a', 'libmp3lame', '-qscale:a', '3', mp3Path]);
+  } catch (e) {
+    console.warn('mp3 encode with filters failed (silence?), retrying plain:', String(e.message).slice(0, 200));
+    await pexec('ffmpeg', ['-y', '-i', c.wavPath,
+      '-codec:a', 'libmp3lame', '-qscale:a', '3', mp3Path]);
+  }
 
   // Move the wav into REC_DIR (rootfs — survives a reboot); it is NOT left in
   // /tmp, so a crash during transcription can no longer lose it.