Fix invisible window when navigating to a deleted route

The Electron window only showed via an IPC signal from the dashboard
layout. If localStorage had a stale URL pointing to a removed route,
the 404 page rendered outside the dashboard layout, the signal never
fired, and the window stayed hidden forever.

Two fixes:
- electron/main.ts: add a 5s fallback timeout to show the window even
  if the renderer never signals ready
- src/app/not-found.tsx: global 404 handler that clears stale nav state
  and redirects to /dashboard

Author: nickustinov

electron/main.ts

@@ -551,15 +551,24 @@ function createWindow(port: number): void {
   const origin = isDev ? `http://127.0.0.1:${port}` : "app://itsyconnect";
   mainWindow.loadURL(`${origin}/`);
 
-  ipcMain.once("app-ready", () => {
+  let shown = false;
+  const showWindow = () => {
+    if (shown) return;
+    shown = true;
     mainWindow?.show();
     // Replay cached update status so the renderer doesn't miss events that
     // fired before it mounted (e.g. update-downloaded on relaunch)
     if (lastUpdateStatus) {
       console.log("[updater] replaying cached status:", lastUpdateStatus.state);
       mainWindow?.webContents.send("update-status", lastUpdateStatus);
     }
-  });
+  };
+
+  ipcMain.once("app-ready", showWindow);
+
+  // Fallback: show the window even if the renderer never signals ready
+  // (e.g. navigated to a 404 page outside the dashboard layout)
+  setTimeout(showWindow, 5000);
 
   let saveTimeout: ReturnType<typeof setTimeout> | null = null;
   const debouncedSave = () => {

package-lock.json

@@ -0,0 +1,16 @@
+"use client";
+
+import { useEffect } from "react";
+import { useRouter } from "next/navigation";
+import { clearNavigation } from "@/lib/nav-state";
+
+export default function NotFound() {
+  const router = useRouter();
+
+  useEffect(() => {
+    clearNavigation();
+    router.replace("/dashboard");
+  }, [router]);
+
+  return null;
+}