fix(exam): print real MCQ options, evaluation-method-aware cutting point check

Print showed blank A/B/C/D fill-in lines for every CHOICE question instead
of the real options — the detail page never fetched option data at all
(GET /exams/:id?i=questions, no nested options), and the print template
hardcoded the blanks regardless. Now requests
?i=questions,questions.options and prints the real option text, falling
back to blank lines only when a question genuinely has none on record.

Also fixed the print-time cutting-point guard: it compared raw point sum
to cutting point regardless of evaluationMethod, wrongly blocking valid
low-point-sum PERCENTAGE papers from printing. Now branches the same way
RecordResultModal's grading preview already does, and surfaces the
matching backend validation error (paper_cannot_reach_cutting_point) added
server-side for the same reason.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/backoffice/src/app/features/exam/api/exam-api.ts

@@ -20,7 +20,9 @@ const examApi = baseApi.injectEndpoints({
       providesTags: ['Api'],
     }),
     getExam: builder.query<Exam, string>({
-      query: (id) => `/exams/${id}?i=questions`,
+      // Nested relation so CHOICE questions carry their options here too —
+      // needed to print real answer choices instead of blank A/B/C/D lines.
+      query: (id) => `/exams/${id}?i=questions,questions.options`,
       providesTags: ['Api'],
     }),
     createExam: builder.mutation<Exam, CreateExamPayload>({