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/hooks/use-metrics.ts

@@ -1,6 +1,6 @@
 import { useState, useEffect, useTransition, useCallback } from 'react';
 import { getWeeklyMetrics, getVelocityTrends } from '@/actions/metrics';
-import { WeeklyMetricsOverview, VelocityTrend } from '@/services/metrics';
+import { WeeklyMetricsOverview, VelocityTrend } from '@/services/analytics/metrics';
 
 // Export des types pour les composants
 export type WeeklyMetrics = WeeklyMetricsOverview;