feat(desktop): optional wipe-on-close (Settings -> Sicherheit)

apps/desktop/electron/main.ts

@@ -6,10 +6,11 @@
 // the old Tauri devUrl so nothing in the renderer code needs to change)
 // and from the built dist in packaged mode.
 
-import { app, BrowserWindow, desktopCapturer, Menu, session } from 'electron';
+import { app, BrowserWindow, desktopCapturer, ipcMain, Menu, session } from 'electron';
 import path from 'node:path';
 import { fileURLToPath } from 'node:url';
 
+import { CHANNELS } from './ipc-types';
 import { register as registerAudioLoopback } from './modules/audio-loopback';
 import { register as registerAutostart } from './modules/autostart';
 import { register as registerFsScoped } from './modules/fs-scoped';
@@ -263,6 +264,32 @@ if (!gotLock) {
     registerAudioLoopback(mainWindow);
   });
 
+  // Wipe-on-close: when the user enables it in Settings, the renderer is given
+  // a chance to clear all sensitive caches before the app process exits. If
+  // the renderer doesn't ack within 2 seconds we force-quit anyway — better
+  // to lose the wipe than to hang the app shutdown.
+  //
+  // Note: there's a separate `before-quit` listener in modules/tray.ts that
+  // tears down the Tray instance. Electron fires both; the tray listener is
+  // synchronous and doesn't touch event.preventDefault, so it doesn't fight
+  // our deferred-quit dance here. The `wipeRequested` flag guards re-entry
+  // when our own `app.quit()` below fires `before-quit` a second time.
+  let wipeRequested = false;
+  app.on('before-quit', (event) => {
+    if (wipeRequested) return;
+    if (!mainWindow || mainWindow.isDestroyed()) return;
+    wipeRequested = true;
+    event.preventDefault();
+
+    mainWindow.webContents.send(CHANNELS.APP_WIPE_BEFORE_QUIT);
+    const done = new Promise<void>((resolve) => {
+      ipcMain.once(CHANNELS.APP_WIPE_BEFORE_QUIT + ':done', () => resolve());
+    });
+    void Promise.race([done, new Promise<void>((r) => setTimeout(r, 2000))]).finally(() => {
+      app.quit();
+    });
+  });
+
   app.on('window-all-closed', () => {
     if (process.platform !== 'darwin') app.quit();
   });