feat: refactor service organization and update imports

- Introduced a new structure for services in `src/services/` to improve organization by domain, including core, analytics, data management, integrations, and task management.
- Moved relevant files to their new locations and updated all internal and external imports accordingly.
- Updated `TODO.md` to reflect the new service organization and outlined phases for further refactoring.

src/app/jira-dashboard/page.tsx

@@ -1,4 +1,4 @@
-import { userPreferencesService } from '@/services/user-preferences';
+import { userPreferencesService } from '@/services/core/user-preferences';
 import { JiraDashboardPageClient } from './JiraDashboardPageClient';
 
 // Force dynamic rendering