chore: refactor project structure and clean up unused components

- Updated `TODO.md` to reflect new testing tasks and final structure expectations.
- Simplified TypeScript path mappings in `tsconfig.json` for better clarity.
- Revised business logic separation rules in `.cursor/rules` to align with new directory structure.
- Deleted unused client components and services to streamline the codebase.
- Adjusted import paths in scripts to match the new structure.

scripts/backup-manager.ts

@@ -4,8 +4,8 @@
  * Usage: tsx scripts/backup-manager.ts [command] [options]
  */
 
-import { backupService, BackupConfig } from '../services/backup';
-import { backupScheduler } from '../services/backup-scheduler';
+import { backupService, BackupConfig } from '../src/services/backup';
+import { backupScheduler } from '../src/services/backup-scheduler';
 
 interface CliOptions {
   command: string;