feat: improve TaskCard and TagList components, enhance task loading logic

- Updated TaskCard to conditionally render footer elements based on available data (due date, source, completion status).
- Enhanced TagList to visually indicate deleting tags and improved button styles for better UX.
- Modified useTasks hook to refresh tasks only if no initial data is present, optimizing loading behavior.
- Updated TagsPageClient to manage local tags and handle optimistic UI updates during tag deletion.

components/kanban/TaskCard.tsx

@@ -186,32 +186,36 @@ export function TaskCard({ task, onDelete, onEdit, onUpdateTitle }: TaskCardProp
         </div>
       )}
 
-      {/* Footer tech avec séparateur néon */}
-      <div className="pt-2 border-t border-slate-700/50">
-        <div className="flex items-center justify-between text-xs">
-          {task.dueDate ? (
-            <span className="flex items-center gap-1 text-slate-400 font-mono">
-              <span className="text-cyan-400">⏰</span>
-              {formatDistanceToNow(new Date(task.dueDate), { 
-                addSuffix: true, 
-                locale: fr 
-              })}
-            </span>
-          ) : (
-            <span className="text-slate-600 font-mono">--:--</span>
-          )}
-          
-          {task.source !== 'manual' && task.source && (
-            <Badge variant="outline" size="sm">
-              {task.source}
-            </Badge>
-          )}
-          
-          {task.completedAt && (
-            <span className="text-emerald-400 font-mono font-bold">✓ DONE</span>
-          )}
+      {/* Footer tech avec séparateur néon - seulement si des données à afficher */}
+      {(task.dueDate || (task.source && task.source !== 'manual') || task.completedAt) && (
+        <div className="pt-2 border-t border-slate-700/50">
+          <div className="flex items-center justify-between text-xs">
+            {task.dueDate ? (
+              <span className="flex items-center gap-1 text-slate-400 font-mono">
+                <span className="text-cyan-400">⏰</span>
+                {formatDistanceToNow(new Date(task.dueDate), { 
+                  addSuffix: true, 
+                  locale: fr 
+                })}
+              </span>
+            ) : (
+              <div></div>
+            )}
+            
+            <div className="flex items-center gap-2">
+              {task.source !== 'manual' && task.source && (
+                <Badge variant="outline" size="sm">
+                  {task.source}
+                </Badge>
+              )}
+              
+              {task.completedAt && (
+                <span className="text-emerald-400 font-mono font-bold">✓ DONE</span>
+              )}
+            </div>
+          </div>
         </div>
-      </div>
+      )}
     </Card>
   );
 }