deploy: add Dockerfile + nginx config for static hosting

The web/ directory is fully self-contained (index.html + worklet.js, all JS
deps pulled from esm.sh via the importmap). Package it as a tiny nginx:alpine
image so Coolify can build + serve it behind Caddy.

- Dockerfile: nginx:1.27-alpine, copies web/ to the document root, healthcheck.
- nginx.conf: serves /, no-cache for index.html and worklet.js (so engine
  changes land immediately after a redeploy), short cache for everything else,
  gzip on text payloads, JS MIME for AudioWorklet.
- .dockerignore: keep the image small (excludes Python sources, docs,
  references, sandbox is included since it's served from /sandbox/).

.dockerignore

@@ -0,0 +1,16 @@
+.git
+.gitignore
+__pycache__/
+*.pyc
+*.pyo
+.venv/
+venv/
+.idea/
+.vscode/
+*.swp
+*.tmp
+referencias/
+docs/
+code_sinth/
+run.py
+*.md