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.

src/index.js

@@ -1,3 +1,5 @@
+const fs = require('fs');
+const path = require('path');
 const express = require('express');
 const { WebshareClient } = require('./webshare');
 const { caps, feed } = require('./torznab');
@@ -113,8 +115,13 @@ app.get('/resolve/:ident', async (req, res) => {
     }
 });
 
-// ── UI static files ────────────────────────────────────────────────────────
-app.use(express.static('ui'));
+// ── UI static files (dev: ../ui from src/; production: dist/ui next to server.js)
+const uiRoot =
+  process.env.UI_DIR ||
+  (fs.existsSync(path.join(__dirname, 'ui'))
+    ? path.join(__dirname, 'ui')
+    : path.join(__dirname, '..', 'ui'));
+app.use(express.static(uiRoot));
 
 // ── UI API: JSON search ───────────────────────────────────────────────────
 app.get('/api/search', async (req, res) => {