feat: update Jira components with improved color schemes and UI enhancements

- Refined color schemes in `BurndownChart`, `CollaborationMatrix`, `ThroughputChart`, and `TeamActivityHeatmap` for better visibility and consistency.
- Adjusted opacity handling in `TeamActivityHeatmap` for improved visual clarity.
- Cleaned up imports in `CollaborationMatrix` and `SprintComparison` for better code organization.
- Enhanced `JiraSync` component with updated color for the sync status indicator.
- Updated `jira-period-filter` to remove unused imports, streamlining the codebase.

components/jira/TeamActivityHeatmap.tsx

@@ -21,21 +21,21 @@ export function TeamActivityHeatmap({ workloadByAssignee, statusDistribution, cl
   // Couleurs pour les différents types de travail
   const getWorkloadColor = (todo: number, inProgress: number, review: number) => {
     const total = todo + inProgress + review;
-    if (total === 0) return 'bg-[var(--muted)]/20';
+    if (total === 0) return null; // Géré séparément
     
-    // Dominante par type de travail
+    // Dominante par type de travail avec couleurs CSS directes (versions plus douces)
     if (review > inProgress && review > todo) {
-      return 'bg-purple-500'; // Review dominant
+      return '#a855f7'; // purple-500 - Review dominant (plus doux)
     } else if (inProgress > todo) {
-      return 'bg-orange-500'; // In Progress dominant
+      return '#f59e0b'; // amber-500 - In Progress dominant (plus doux)
     } else {
-      return 'bg-blue-500'; // Todo dominant
+      return '#3b82f6'; // blue-500 - Todo dominant (plus doux)
     }
   };
 
   const getOpacity = (total: number) => {
     const intensity = getIntensity(total);
-    return Math.max(0.2, intensity / 100);
+    return Math.max(0.6, Math.min(0.9, intensity / 100)); // Opacité plus élevée et moins de variation
   };
 
   return (
@@ -45,28 +45,37 @@ export function TeamActivityHeatmap({ workloadByAssignee, statusDistribution, cl
         <div>
           <h4 className="text-sm font-medium mb-3">Intensité de travail par membre</h4>
           <div className="grid grid-cols-2 md:grid-cols-3 lg:grid-cols-4 gap-2">
-            {workloadByAssignee.map(assignee => (
-              <div
-                key={assignee.assignee}
-                className="relative p-3 rounded-lg border border-[var(--border)] transition-all hover:scale-105"
-                style={{
-                  backgroundColor: getWorkloadColor(assignee.todoCount, assignee.inProgressCount, assignee.reviewCount),
-                  opacity: getOpacity(assignee.totalActive)
-                }}
-              >
-                <div className="text-white text-xs font-medium mb-1 truncate">
+            {workloadByAssignee.map(assignee => {
+              const bgColor = getWorkloadColor(assignee.todoCount, assignee.inProgressCount, assignee.reviewCount);
+              const isEmpty = assignee.totalActive === 0;
+              
+              return (
+                <div
+                  key={assignee.assignee}
+                  className={`relative p-3 rounded-lg border border-[var(--border)] transition-all hover:scale-105 ${
+                    isEmpty ? 'bg-[var(--muted)]/30' : ''
+                  }`}
+                  style={bgColor ? {
+                    backgroundColor: bgColor,
+                    opacity: getOpacity(assignee.totalActive)
+                  } : {
+                    opacity: getOpacity(assignee.totalActive)
+                  }}
+                >
+                <div className={isEmpty ? "text-[var(--foreground)] text-xs font-medium mb-1 truncate" : "text-white text-xs font-medium mb-1 truncate"}>
                   {assignee.displayName}
                 </div>
-                <div className="text-white text-lg font-bold">
+                <div className={isEmpty ? "text-[var(--foreground)] text-lg font-bold" : "text-white text-lg font-bold"}>
                   {assignee.totalActive}
                 </div>
-                <div className="text-white/80 text-xs">
+                <div className={isEmpty ? "text-[var(--muted-foreground)] text-xs" : "text-white/80 text-xs"}>
                   {assignee.todoCount > 0 && `${assignee.todoCount} à faire`}
                   {assignee.inProgressCount > 0 && ` ${assignee.inProgressCount} en cours`}
                   {assignee.reviewCount > 0 && ` ${assignee.reviewCount} review`}
                 </div>
               </div>
-            ))}
+              );
+            })}
           </div>
         </div>
 
@@ -77,7 +86,7 @@ export function TeamActivityHeatmap({ workloadByAssignee, statusDistribution, cl
             <span>À faire dominant</span>
           </div>
           <div className="flex items-center gap-2">
-            <div className="w-3 h-3 bg-orange-500 rounded"></div>
+            <div className="w-3 h-3 bg-amber-500 rounded"></div>
             <span>En cours dominant</span>
           </div>
           <div className="flex items-center gap-2">