Add speech-to-text feature using Faster Whisper container

Adds a mic button to the terminal UI that captures speech, transcribes
it via a Faster Whisper sidecar container, and injects the text into
the terminal input. Includes settings panel for model selection
(tiny/small/medium), port config, and container lifecycle management.

- stt-container/: Dockerfile + FastAPI server for Whisper transcription
- Rust backend: STT container management, transcribe_audio IPC command
- Frontend: useSTT hook, SttButton, SttSettings, WAV encoder
- CI: Gitea Actions workflow for multi-arch STT image builds

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/build-stt.yml

@@ -0,0 +1,59 @@
+name: Build STT Container
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - "stt-container/**"
+      - ".gitea/workflows/build-stt.yml"
+  pull_request:
+    branches: [main]
+    paths:
+      - "stt-container/**"
+      - ".gitea/workflows/build-stt.yml"
+
+env:
+  REGISTRY: repo.anhonesthost.net
+  IMAGE_NAME: cybercovellc/triple-c/triple-c-stt
+
+jobs:
+  build-stt-container:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Gitea Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ gitea.actor }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: shadowdao
+          password: ${{ secrets.GH_PAT }}
+
+      - name: Build and push STT container image
+        uses: docker/build-push-action@v5
+        with:
+          context: ./stt-container
+          file: ./stt-container/Dockerfile
+          platforms: linux/amd64,linux/arm64
+          push: ${{ gitea.event_name == 'push' }}
+          tags: |
+            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
+            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ gitea.sha }}
+            ghcr.io/shadowdao/triple-c-stt:latest
+            ghcr.io/shadowdao/triple-c-stt:${{ gitea.sha }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max