fix(desktop): tray badge — IPC handler died when icon.ico missing from packaged resources

apps/desktop/electron/modules/tray.ts

@@ -30,6 +30,17 @@ function resolveIconPathDev(): string {
   return path.join(app.getAppPath(), 'resources', 'icon.ico');
 }
 
+// 16×16 grey square — last-ditch fallback when neither the packaged
+// nor dev icon file resolves. Tray constructor on Windows throws when
+// handed an empty NativeImage, which would tear down the whole
+// registrar before `ipcMain.handle(TRAY_UNREAD)` runs — leaving the
+// taskbar overlay badge wired but the renderer's invoke rejecting
+// with "No handler registered". A non-empty placeholder keeps the
+// constructor happy so the IPC handler always gets registered.
+const FALLBACK_TRAY_PNG_BASE64 =
+  'iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAAH0lEQVR42mNk' +
+  'YGD4z0ABYBxVOKpwVOGowlGFwwoBAEnYAR9XlIldAAAAAElFTkSuQmCC';
+
 function loadTrayIcon(): NativeImage {
   for (const p of [resolveIconPath(), resolveIconPathDev()]) {
     try {
@@ -39,7 +50,7 @@ function loadTrayIcon(): NativeImage {
       /* try next */
     }
   }
-  return nativeImage.createEmpty();
+  return nativeImage.createFromBuffer(Buffer.from(FALLBACK_TRAY_PNG_BASE64, 'base64'));
 }
 
 function buildOverlay(): NativeImage {
@@ -53,8 +64,16 @@ function buildOverlay(): NativeImage {
 }
 
 export function register(mainWindow: BrowserWindow): void {
+  // Tray icon is best-effort: if neither the packaged resource nor the
+  // dev path resolves (e.g. icon.ico isn't shipped under resourcesPath
+  // in packaged builds — only the app icon goes into the .exe metadata),
+  // we still want the taskbar overlay badge to work. setOverlayIcon is
+  // a BrowserWindow method, so it functions even when the systray icon
+  // creation fails.
+  try {
     const icon = loadTrayIcon();
-  trayRef = new Tray(icon.isEmpty() ? nativeImage.createEmpty() : icon);
+    if (!icon.isEmpty()) {
+      trayRef = new Tray(icon);
       trayRef.setToolTip('Netralax');
 
       const menu = Menu.buildFromTemplate([
@@ -82,6 +101,12 @@ export function register(mainWindow: BrowserWindow): void {
         if (mainWindow.isVisible()) mainWindow.focus();
         else mainWindow.show();
       });
+    }
+  } catch (err: unknown) {
+    // Swallow: the overlay badge below is the user-visible bit. A missing
+    // systray icon is cosmetic and shouldn't take the unread handler with it.
+    console.warn('[tray] systray init failed, overlay badge still active', err);
+  }
 
   ipcMain.handle(
     CHANNELS.TRAY_UNREAD,