feat: add voice mode support via mic passthrough to container

Enables Claude Code's /voice command inside Docker containers by
capturing microphone audio in the Tauri webview and streaming it
into the container via a FIFO pipe.

Container: fake rec/arecord shims read PCM from a FIFO instead of
a real mic. Audio bridge exec writes PCM from Tauri into the FIFO.
Frontend: getUserMedia() + AudioWorklet captures 16kHz mono PCM
and streams it to the container via invoke("send_audio_data").
UI: "Mic Off/On" toggle button in the terminal view.

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

container/Dockerfile

@@ -111,6 +111,14 @@ RUN chmod +x /usr/local/bin/osc52-clipboard \
     && ln -sf /usr/local/bin/osc52-clipboard /usr/local/bin/xsel \
     && ln -sf /usr/local/bin/osc52-clipboard /usr/local/bin/pbcopy
 
+# ── Audio capture shim (voice mode) ────────────────────────────────────────
+# Provides fake rec/arecord that read PCM from a FIFO instead of a real mic,
+# allowing Claude Code voice mode to work inside the container.
+COPY audio-shim /usr/local/bin/audio-shim
+RUN chmod +x /usr/local/bin/audio-shim \
+    && ln -sf /usr/local/bin/audio-shim /usr/local/bin/rec \
+    && ln -sf /usr/local/bin/audio-shim /usr/local/bin/arecord
+
 COPY entrypoint.sh /usr/local/bin/entrypoint.sh
 RUN chmod +x /usr/local/bin/entrypoint.sh
 COPY triple-c-scheduler /usr/local/bin/triple-c-scheduler