feat: complete Phase 2 of service refactoring

- Marked tasks in `TODO.md` as completed for moving analytics-related files to the `analytics` directory and correcting imports across the codebase.
- Updated imports in `src/actions/analytics.ts`, `src/actions/metrics.ts`, and various components to reflect the new structure.
- Removed unused `analytics.ts`, `manager-summary.ts`, and `metrics.ts` files to streamline the codebase.

src/components/dashboard/charts/ProductivityInsights.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { DailyMetrics } from '@/services/metrics';
+import { DailyMetrics } from '@/services/analytics/metrics';
 
 interface ProductivityInsightsProps {
   data: DailyMetrics[];