Add esbuild production bundle and multi-stage slim Docker image.

Bundle server (and mcp entry) into a single JS file with deps inlined, minify UI into one HTML, and ship only dist/ in the runtime image.

README.md

@@ -19,22 +19,34 @@ Webshare download links expire after roughly ten minutes, so the torrent never e
 ## Layout
 
 ```
-src/
-  index.js       # Express app + optional Sonarr missing-episode search
-  webshare.js    # salt/login, search, file_link
-  md5crypt.js    # Unix $1$ MD5-crypt (Webshare password digest)
-  torznab.js     # caps + search feed XML
-  torrent.js     # bencode + fake torrent + info-hash
-  qbt.js         # qBittorrent Web API façade + download queue
-  mcp-server.js  # MCP tool registration (shared)
-  mcp-http.js    # Streamable HTTP transport mount for Express
-  mcp.js         # Optional MCP-only HTTP process
-  ui/            # Web UI: search & queue management
+src/             # source (CommonJS modules)
+ui/              # Web UI source (index.html, styles.css, scripts.js)
+scripts/build.mjs # esbuild: single server.js + minified single-file UI
+dist/            # build output (gitignored; produced by npm run build / Docker)
+  server.js      # one file: app + all npm dependencies
+  mcp.js         # optional MCP-only entry
+  ui/index.html  # CSS+JS inlined
 __tests__/
 compose.yaml
-Dockerfile
+Dockerfile       # multi-stage: build with esbuild, runtime = Node + dist only
 ```
 
+## Build (smaller image / single JS)
+
+```bash
+npm install
+npm run build    # → dist/server.js (~2 MB, all deps bundled) + dist/ui/index.html
+npm start        # node dist/server.js
+npm run start:dev # unbundled src/ for local hacking
+```
+
+**esbuild** bundles the server (and optional `mcp` entry) into a **single `.js` file** with
+dependencies inlined — no `node_modules` needed at runtime. The Web UI is minified into
+**one** `dist/ui/index.html` (CSS and JS inlined).
+
+Docker uses a multi-stage build: final image copies only `dist/`, not source or
+`node_modules`, which keeps the image much smaller than `npm ci --omit=dev`.
+
 ## Configuration
 
 Environment variables (required unless noted):
@@ -71,9 +83,11 @@ See `compose.yaml`. Override ports, `BASE_URL`, Sonarr settings, and volume moun
 
 ```bash
 npm install
+npm run build
 export WEBSHARE_USERNAME=...
 export WEBSHARE_PASSWORD=...
 npm start
+# or: npm run start:dev  # no build step, uses src/
 ```
 
 ## Sonarr / Radarr