Move tray state into createTray closure

Removes top-level let trayInstance, opts, currentTitle, currentArtist
and the top-level buildMenu function. All mutable state and buildMenu
now live inside the createTray closure. Public API and behaviour are
unchanged.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

desktop-client/tray.js

@@ -14,30 +14,6 @@ const TRAY_ICON_BASE64 =
   'PB7S4/EuoISgYrLKD1dOhOPFP6+4R7ieoQPNv9/ULZ+zfis+0Y1e+F7oF3H5F+Xt' +
   'T5p0AqBYeEeEF8k/gtcS56z6f/E5UOLHL8A8a4yC0IHbH4AAAAASUVORK5CYII=';
 
-let trayInstance = null;
-let opts = null;
-let currentTitle = null;
-let currentArtist = null;
-
-function buildMenu() {
-  const url = `http://localhost:${opts.port}/`;
-  const nowPlaying =
-    currentTitle && currentArtist
-      ? `${currentTitle} — ${currentArtist}`
-      : currentTitle || 'Nothing playing';
-
-  return Menu.buildFromTemplate([
-    { label: "What's That Music", enabled: false },
-    { label: `Now Playing: ${nowPlaying}`, enabled: false },
-    { type: 'separator' },
-    { label: 'Show Player', click: () => opts.onShow && opts.onShow() },
-    { label: 'Open Overlay in Browser', click: () => shell.openExternal(url) },
-    { label: 'Copy OBS URL', click: () => clipboard.writeText(url) },
-    { type: 'separator' },
-    { label: 'Quit', click: () => opts.onQuit && opts.onQuit() },
-  ]);
-}
-
 /**
  * @param {Object} options
  * @param {number} options.port
@@ -45,8 +21,29 @@ function buildMenu() {
  * @param {() => void} options.onQuit
  * @returns {{ update: (info: { title: string|null, artist: string|null }) => void, destroy: () => void }}
  */
-function createTray(options) {
-  opts = options;
+function createTray({ port, onShow, onQuit }) {
+  let trayInstance = null;
+  let currentTitle = null;
+  let currentArtist = null;
+
+  function buildMenu() {
+    const url = `http://localhost:${port}/`;
+    const nowPlaying =
+      currentTitle && currentArtist
+        ? `${currentTitle} — ${currentArtist}`
+        : currentTitle || 'Nothing playing';
+
+    return Menu.buildFromTemplate([
+      { label: "What's That Music", enabled: false },
+      { label: `Now Playing: ${nowPlaying}`, enabled: false },
+      { type: 'separator' },
+      { label: 'Show Player', click: () => onShow && onShow() },
+      { label: 'Open Overlay in Browser', click: () => shell.openExternal(url) },
+      { label: 'Copy OBS URL', click: () => clipboard.writeText(url) },
+      { type: 'separator' },
+      { label: 'Quit', click: () => onQuit && onQuit() },
+    ]);
+  }
 
   const icon = nativeImage.createFromDataURL(TRAY_ICON_BASE64);
   icon.setTemplateImage(true);