feat: implement initial Electron chat application with core UI components and Convex backend integration.

Frontend/Electron/main.cjs

@@ -79,6 +79,11 @@ function createWindow() {
 
     // Save window state on close
     mainWindow.on('close', () => {
+        // Flush localStorage/sessionStorage to disk before renderer is destroyed
+        // (Chromium writes to an in-memory cache and flushes asynchronously;
+        // without this, data written just before close can be lost)
+        mainWindow.webContents.session.flushStorageData();
+
         const current = loadSettings(); // re-read to preserve theme changes
         if (!mainWindow.isMaximized()) {
             const bounds = mainWindow.getBounds();