Fix: Resolve blank Electron window and implement proper dev server startup

- Add wait-on package to ensure Vite dev server starts before Electron
- Configure Vite with strict port binding to prevent port conflicts
- Update dev:all script to wait for http://localhost:5173 before launching Electron

This fixes the issue where Electron would open a blank window because it tried
to connect to the Vite dev server before it was ready, causing a port conflict.
The sequential startup ensures the dev server is fully operational before
Electron attempts to connect.

Fixes: Blank Electron window on npm run dev

Author: nicholaspsmith