Implement settings service and routes for file-based settings management

- Add SettingsService to handle reading/writing global and project settings.
- Introduce API routes for managing settings, including global settings, credentials, and project-specific settings.
- Implement migration functionality to transfer settings from localStorage to file-based storage.
- Create common utilities for settings routes and integrate logging for error handling.
- Update server entry point to include new settings routes.

apps/ui/src/components/views/setup-view/steps/index.ts

@@ -1,5 +1,6 @@
 // Re-export all setup step components for easier imports
 export { WelcomeStep } from "./welcome-step";
+export { ThemeStep } from "./theme-step";
 export { CompleteStep } from "./complete-step";
 export { ClaudeSetupStep } from "./claude-setup-step";
 export { GitHubSetupStep } from "./github-setup-step";