feat: add Docker + web deployment support

[ageofalgo]

feat: Docker + Web Deployment Support

Summary

Adds production-ready Docker support for running Voicebox as a self-contained web service (API + UI) without the Tauri desktop app. This implements the Docker deployment planned in DOCKER_DEPLOYMENT.md.

Motivation

Currently, Voicebox can only be used via the Tauri desktop app or by running the backend manually. This PR enables a simple docker compose up workflow that serves both the API and the web frontend from a single container — useful for headless servers, integration with other local tools, and anyone who doesn't want to install Python/Bun/Rust locally.

Changes

New Files

File	Description
Dockerfile	3-stage build: (1) Bun builds the web/ frontend, (2) Python deps compiled in builder, (3) slim runtime image with both frontend + backend
docker-compose.yml	Localhost-only port binding (17493), bind-mount for audio output, named volumes for data persistence and HuggingFace model cache
.dockerignore	Excludes desktop-only dirs (tauri/, landing/, docs/) and build artifacts for a lean image

Modified Files

File	Change
backend/main.py	Root GET / endpoint now serves index.html when the frontend build is present (Docker), falls back to API JSON otherwise. Added conditional static file serving + SPA catch-all route, only activated when /app/frontend/ exists — zero impact on existing non-Docker usage.

Usage

# Build image
docker compose build

# Start container
docker compose up -d

# Open in browser
open http://localhost:17493

# Check health
curl http://localhost:17493/health

# View logs
docker compose logs -f

# Stop
docker compose down

Generated audio files appear in the ./output/ directory (configurable via the bind-mount in docker-compose.yml).

Architecture

┌──────────────────────────────────────────┐
│            Docker Container              │
│                                          │
│  ┌──────────────────────────────────┐    │
│  │  FastAPI (uvicorn :17493)        │    │
│  │                                  │    │
│  │  GET /         → index.html      │    │
│  │  GET /assets/* → static files    │    │
│  │  GET /health   → health JSON     │    │
│  │  POST /generate → TTS engine     │    │
│  │  GET /*        → SPA catch-all   │    │
│  └──────────────────────────────────┘    │
│                                          │
│  /app/frontend/  ← built web/ React app  │
│  /app/backend/   ← Python FastAPI code   │
│  /app/data/      ← DB, profiles, cache   │
└──────────────────────────────────────────┘
         │
         ├── 127.0.0.1:17493 (localhost only)
         └── ./output/ (bind-mount for audio)

Build Details

The Dockerfile uses a 3-stage build to keep the runtime image small:

1. frontend stage (oven/bun:1): Strips tauri/landing workspaces from package.json, installs deps, runs vite build (skipping tsc due to pre-existing upstream type errors)
2. backend-builder stage (python:3.11-slim): Installs Python deps including Qwen3-TTS into a prefix
3. Runtime stage (python:3.11-slim): Copies built frontend + Python packages, runs as non-root voicebox user with health check

Security

• Port bound to 127.0.0.1 only (not accessible from network)
• Runs as non-root user inside container
• Resource limits (4 CPUs, 8GB RAM) via deploy config
• No changes to existing authentication or CORS behavior

Notes

• The web/ build skips TypeScript checking (tsc) because there are pre-existing type errors in the shared app/ source. Vite handles the build fine without strict type checking. These errors should be fixed upstream separately.
• The frontend static file serving is conditionally activated — it only runs when /app/frontend/ exists (i.e., inside the Docker container). Running the backend outside Docker behaves exactly as before.
• Models are auto-downloaded from HuggingFace on first generation. The huggingface-cache named volume ensures they persist across container rebuilds.

Testing

• docker compose build succeeds
• docker compose up -d starts container
• curl http://localhost:17493/health returns healthy status
• Web UI loads at http://localhost:17493
• API endpoints remain functional
• Running backend outside Docker is unaffected (no /app/frontend/ → JSON response at /)