Adds explicit AppUserModelID for Windows, robust single-instance and protocol URL handling, and protocol registration for http/https in package.json. Enhances default browser logic to handle OS-specific requirements, provides user feedback in the setup UI, and allows opening system settings for default browser selection. Updates preload and renderer logic to support these changes.
Introduces a multi-step onboarding process for first-time users, including theme selection and default browser setup. Adds setup.html, setup.js, and setup.css for the new UI, updates main.js and preload.js to support onboarding logic and IPC handlers, and adjusts theme-manager.js for correct theme directory resolution.
andrew