feat(exam): show candidate answers + prefill auto-scores in RecordResultModal

Wires useGetGradingSheetQuery into the grading modal: a new 'Candidate's
Answer' column shows the selected option or essay text per question, and
whichever CHOICE scores auto-grading could already compute get prefilled
into the score inputs (tagged 'Auto-graded', still editable — the examiner
can override). Grading a mixed or ESSAY paper no longer means guessing at
what was answered or re-deriving the CHOICE portion by eye.

Degrades to blank inputs exactly as before for an OFFLINE candidate or one
who hasn't sat an online attempt (gradingSheet returns empty answers for
those, not an error).

apps/backoffice/src/app/i18n/locales/am.ts

@@ -657,6 +657,9 @@ export const am: Translations = {
       seafarerPlaceholder: "መርከበኛ ይፈልጉ እና ይምረጡ",
       scorePerQuestion: "በጥያቄ ውጤት",
       question: "ጥያቄ",
+      candidateAnswer: "የተፈታኙ መልስ",
+      noAnswer: "የተመዘገበ መልስ የለም",
+      autoGraded: "በራስ-ሰር የተመዘነ",
       maxPoints: "ከፍተኛ ውጤት",
       score: "ውጤት",
       remark: "ማስታወሻ",

apps/backoffice/src/app/i18n/locales/en.ts

@@ -657,6 +657,9 @@ export const en = {
       seafarerPlaceholder: 'Search and select a seafarer',
       scorePerQuestion: 'Score per Question',
       question: 'Question',
+      candidateAnswer: "Candidate's Answer",
+      noAnswer: 'No answer on file',
+      autoGraded: 'Auto-graded',
       maxPoints: 'Max Points',
       score: 'Score',
       remark: 'Remark',