feat: add Docker Sandbox deployment support

Add example and documentation for deploying sandbox-agent inside Docker
Sandbox microVMs for enhanced isolation on macOS/Windows.

- Add examples/docker-sandbox/ with TypeScript example
- Add docs/deploy/docker-sandbox.mdx with setup guide using custom templates
- Update docs navigation to include Docker Sandbox

examples/docker-sandbox/tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "lib": ["ES2022", "DOM"],
+    "module": "ESNext",
+    "moduleResolution": "Bundler",
+    "allowImportingTsExtensions": true,
+    "noEmit": true,
+    "esModuleInterop": true,
+    "strict": true,
+    "skipLibCheck": true,
+    "resolveJsonModule": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "**/*.test.ts"]
+}