P4 app: Digital text viewer + extraction audit chip on setup page

'Digital text' button opens the digital-replica markdown (stem text, parts, marks,
answer-space placeholders, spec refs) in a dialog with download. A 'Marks N/M' chip
surfaces the extraction cover-total reconciliation (green=ok / amber=under-read) from
extraction_meta.audit. examRepository.getDigitalText + DigitalTextResponse type.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

src/services/exam/examRepository.ts

@@ -15,6 +15,7 @@ import type {
   AutoMapResponse,
   BankResponse,
   CorpusResponse,
+  DigitalTextResponse,
   BatchQueueResponse,
   BatchResultsResponse,
   CreateBatchPayload,
@@ -164,6 +165,12 @@ export const examRepository = {
     return res.data.templates ?? [];
   },
 
+  async getDigitalText(templateId: string): Promise<DigitalTextResponse> {
+    const headers = await authHeaders();
+    const res = await axios.get<DigitalTextResponse>(`${EXAM_BASE}/templates/${templateId}/digital-text`, { headers });
+    return res.data;
+  },
+
   async getTemplate(templateId: string): Promise<ExamTemplateDetail> {
     const headers = await authHeaders();
     const res = await axios.get<ExamTemplateDetail>(`${EXAM_BASE}/templates/${templateId}`, { headers });