fix(dev): pin dev server, wait-on gate, and Electron loadURL to 127.0.0.1

With plain localhost, node >=17 can bind the Vite dev server to ::1
only; on this machine IPv4/IPv6 loopback mismatch made the browser,
wait-on, and the Electron window all see connection-refused while Vite
reported ready. Explicit 127.0.0.1 on all three ends fixes dev startup
(user-verified: electron:dev window now opens).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

electron/main.cjs

@@ -34,7 +34,7 @@ function createWindow() {
   })
 
   if (isDev) {
-    win.loadURL('http://localhost:5173')
+    win.loadURL('http://127.0.0.1:5173')
     win.webContents.openDevTools()
   } else {
     win.loadFile(path.join(__dirname, '../dist/index.html'))