feat(frontend): add Rate Partner button and dashboard tests

- Add Rate button to MatchCard (shows when video exchange complete & not rated)
- Add 15 comprehensive tests for DashboardPage component
- Tests cover: loading, empty states, events, matches, requests, navigation

frontend/src/pages/DashboardPage.jsx

@@ -338,6 +338,9 @@ const MatchCard = ({ match }) => {
   const navigate = useNavigate();
   const { partner, event, videoExchange, ratings } = match;
 
+  // Can rate when video exchange is complete and user hasn't rated yet
+  const canRate = videoExchange?.sentByMe && videoExchange?.receivedFromPartner && !ratings?.ratedByMe;
+
   return (
     <div className="bg-white rounded-lg shadow-sm border border-gray-200 p-4 hover:shadow-md transition-shadow">
       <div className="flex items-start gap-4">
@@ -374,14 +377,25 @@ const MatchCard = ({ match }) => {
           </div>
         </div>
 
-        {/* Action */}
-        <button
-          onClick={() => navigate(`/matches/${match.slug}/chat`)}
-          className="flex-shrink-0 flex items-center gap-2 px-4 py-2 bg-primary-600 text-white rounded-md hover:bg-primary-700 transition-colors"
-        >
-          <MessageCircle className="w-4 h-4" />
-          Chat
-        </button>
+        {/* Actions */}
+        <div className="flex-shrink-0 flex flex-col gap-2">
+          <button
+            onClick={() => navigate(`/matches/${match.slug}/chat`)}
+            className="flex items-center gap-2 px-4 py-2 bg-primary-600 text-white rounded-md hover:bg-primary-700 transition-colors"
+          >
+            <MessageCircle className="w-4 h-4" />
+            Chat
+          </button>
+          {canRate && (
+            <button
+              onClick={() => navigate(`/matches/${match.slug}/rate`)}
+              className="flex items-center gap-2 px-4 py-2 border border-amber-500 text-amber-600 rounded-md hover:bg-amber-50 transition-colors"
+            >
+              <Star className="w-4 h-4" />
+              Rate
+            </button>
+          )}
+        </div>
       </div>
     </div>
   );