feat: add favorite task templates and optimize evidence exports

apps/showcase_ui/src/app/components/chat-interface/chat-interface.component.html

@@ -125,8 +125,11 @@ limitations under the License.
               }
             </div>
           </div>
-          <div class="task-goal" title="{{ session.initial_goal }}">
-            {{ session.display_name || session.initial_goal || '未命名任务' }}
+          <div class="task-title-row">
+            <app-favorite-button [sourceId]="session.session_id" />
+            <div class="task-goal" title="{{ session.initial_goal }}">
+              {{ session.display_name || session.initial_goal || '未命名任务' }}
+            </div>
           </div>
           <div class="task-card-footer">
             <app-task-id-copy [taskId]="session.session_id" />