Enhance test submission feature by adding optional hiddenInstructions field for temporary instructions during LLM checks; update API, UI components, and types to support this functionality, improving task evaluation for teachers and challenge authors.

src/__data__/api/api.ts

@@ -147,7 +147,7 @@ export const api = createApi({
 
     // Test submission (LLM check without creating a real submission)
     testSubmission: builder.mutation<TestSubmissionResult, SubmitRequest>({
-      query: ({ userId, taskId, result, isTest = true }) => ({
+      query: ({ userId, taskId, result, isTest = true, hiddenInstructions }) => ({
         url: '/challenge/submit',
         method: 'POST',
         body: {
@@ -155,6 +155,7 @@ export const api = createApi({
           taskId,
           result,
           isTest,
+          hiddenInstructions,
         },
       }),
       transformResponse: (response: APIResponse<TestSubmissionResult>) => response.data,