Fix needs-work feedback panel closing immediately

The IssueChatCtx.Provider was opened but never closed, causing the
context to not properly wrap the thread. This, combined with the
stable component references via context (already in place), ensures
OutputFeedbackButtons state is preserved across re-renders when
feedback votes update.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/components/IssueChatThread.tsx

@@ -1054,6 +1054,7 @@ export function IssueChatThread({
           />
         ) : null}
       </div>
+      </IssueChatCtx.Provider>
     </AssistantRuntimeProvider>
   );
 }