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/components/dashboard/ProductivityAnalytics.tsx

@@ -1,21 +1,24 @@
 import { useMemo } from 'react';
 import { ProductivityMetrics } from '@/services/analytics/analytics';
 import { DeadlineMetrics } from '@/services/analytics/deadline-analytics';
+import { TagDistributionMetrics } from '@/services/analytics/tag-analytics';
 import { CompletionTrendChart } from '@/components/charts/CompletionTrendChart';
 import { VelocityChart } from '@/components/charts/VelocityChart';
 import { PriorityDistributionChart } from '@/components/charts/PriorityDistributionChart';
 import { WeeklyStatsCard } from '@/components/charts/WeeklyStatsCard';
+import { TagDistributionChart } from '@/components/dashboard/TagDistributionChart';
 import { Card, MetricCard } from '@/components/ui';
 import { DeadlineOverview } from '@/components/deadline/DeadlineOverview';
 
 interface ProductivityAnalyticsProps {
   metrics: ProductivityMetrics;
   deadlineMetrics: DeadlineMetrics;
+  tagMetrics: TagDistributionMetrics;
   selectedSources: string[];
   hiddenSources?: string[];
 }
 
-export function ProductivityAnalytics({ metrics, deadlineMetrics, selectedSources, hiddenSources = [] }: ProductivityAnalyticsProps) {
+export function ProductivityAnalytics({ metrics, deadlineMetrics, tagMetrics, selectedSources, hiddenSources = [] }: ProductivityAnalyticsProps) {
 
   // Filtrer les métriques selon les sources sélectionnées
   const filteredMetrics = useMemo(() => {
@@ -133,6 +136,9 @@ export function ProductivityAnalytics({ metrics, deadlineMetrics, selectedSource
         </Card>
       </div>
 
+      {/* Distribution par Tags */}
+      <TagDistributionChart metrics={tagMetrics} />
+
       {/* Insights automatiques */}
       <Card className="p-6">
         <h3 className="text-lg font-semibold mb-4">💡 Insights</h3>