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>

vite.config.js

@@ -6,6 +6,9 @@ export default defineConfig({
   plugins: [react(), tailwindcss()],
   base: './',   // relative paths so Electron can load files from disk
   server: {
+    // Explicit IPv4 bind: with plain `localhost`, node ≥17 can bind ::1 only,
+    // which browsers/wait-on may fail to reach (seen on Windows + node 24).
+    host: '127.0.0.1',
     port: 5173,
   },
   build: {