feat: enhance HomePage with tag metrics and analytics integration

- Added TagAnalyticsService to fetch tag distribution metrics for the HomePage.
- Updated HomePageClient and ProductivityAnalytics components to utilize new tag metrics.
- Refactored TagsClient to use utility functions for color validation and generation.
- Simplified TagForm to use centralized tag colors from TAG_COLORS.

src/app/page.tsx

@@ -2,6 +2,7 @@ import { tasksService } from '@/services/task-management/tasks';
 import { tagsService } from '@/services/task-management/tags';
 import { AnalyticsService } from '@/services/analytics/analytics';
 import { DeadlineAnalyticsService } from '@/services/analytics/deadline-analytics';
+import { TagAnalyticsService } from '@/services/analytics/tag-analytics';
 import { HomePageClient } from '@/components/HomePageClient';
 
 // Force dynamic rendering (no static generation)
@@ -9,12 +10,13 @@ export const dynamic = 'force-dynamic';
 
 export default async function HomePage() {
   // SSR - Récupération des données côté serveur
-  const [initialTasks, initialTags, initialStats, productivityMetrics, deadlineMetrics] = await Promise.all([
+  const [initialTasks, initialTags, initialStats, productivityMetrics, deadlineMetrics, tagMetrics] = await Promise.all([
     tasksService.getTasks(),
     tagsService.getTags(),
     tasksService.getTaskStats(),
     AnalyticsService.getProductivityMetrics(),
-    DeadlineAnalyticsService.getDeadlineMetrics()
+    DeadlineAnalyticsService.getDeadlineMetrics(),
+    TagAnalyticsService.getTagDistributionMetrics()
   ]);
 
   return (
@@ -24,6 +26,7 @@ export default async function HomePage() {
       initialStats={initialStats}
       productivityMetrics={productivityMetrics}
       deadlineMetrics={deadlineMetrics}
+      tagMetrics={tagMetrics}
     />
   );
 }