Fix black screen: wait for Vite before Electron, retry loadURL, show boot fallback.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/main/index.ts

@@ -69,9 +69,37 @@ function createWindow(): void {
     },
   });
 
+  mainWindow.once('ready-to-show', () => {
+    mainWindow?.show();
+    mainWindow?.focus();
+  });
+  mainWindow.show();
+
   const devUrl = process.env.VITE_DEV_SERVER_URL;
   if (devUrl) {
-    void mainWindow.loadURL(devUrl);
+    mainWindow.webContents.openDevTools({ mode: 'detach' });
+    mainWindow.webContents.on('did-fail-load', (_e, code, desc, url) => {
+      console.error('did-fail-load', code, desc, url);
+    });
+    mainWindow.webContents.on('console-message', (_e, level, message) => {
+      console.log(`[renderer:${level}]`, message);
+    });
+    const load = async (attempt = 0) => {
+      try {
+        await mainWindow!.loadURL(devUrl);
+        console.log('Loaded', devUrl);
+      } catch (err) {
+        console.error('loadURL attempt', attempt, err);
+        if (attempt < 20) {
+          setTimeout(() => void load(attempt + 1), 300);
+          return;
+        }
+        await mainWindow!.loadURL(
+          `data:text/html,<h1 style="color:#fff;font-family:sans-serif;padding:24px">Dev server not reachable: ${devUrl}</h1>`,
+        );
+      }
+    };
+    void load();
   } else {
     void mainWindow.loadFile(path.join(__dirname, '../renderer/index.html'));
   }