Add a thin grey border around validation icons

Apply a border to various check and check circle icons across different modals and pages to visually distinguish them.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: b163d4c0-de5e-4f4e-a9c0-aed4c7049718
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/b163d4c0-de5e-4f4e-a9c0-aed4c7049718/93Mucz1

client/src/pages/Tasks.tsx

@@ -445,7 +445,7 @@ export default function Tasks() {
                                         {task.title}
                                       </h5>
                                       <Badge variant="secondary" className="flex items-center gap-1">
-                                        <CheckCircle className="w-3 h-3" />
+                                        <CheckCircle className="w-3 h-3 border border-gray-300 rounded p-0.5" />
                                         Terminée
                                       </Badge>
                                     </div>