feat: add notes functionality to exam state and update UI for note-taking

backend/src/routes/results.ts

@@ -67,7 +67,7 @@ router.get('/:id', requireAuth, (req, res) => {
 // ─── Save Result ─────────────────────────────────────────
 router.post('/', requireAuth, (req, res) => {
   try {
-    const { title, scorePoints, totalPoints, correctCount, gradedCount, passingScore, elapsedMs, state, exam, examId } = req.body
+    const { title, scorePoints, totalPoints, correctCount, gradedCount, passingScore, elapsedMs, notes, state, exam, examId } = req.body
 
     if (
       !title || scorePoints == null || totalPoints == null ||
@@ -77,6 +77,17 @@ router.post('/', requireAuth, (req, res) => {
       return
     }
 
+    let noteSource = ''
+    if (typeof notes === 'string') {
+      noteSource = notes
+    } else if (typeof state.notes === 'string') {
+      noteSource = state.notes
+    }
+    const normalizedState = {
+      ...state,
+      notes: noteSource.slice(0, 1000),
+    }
+
     const db = getDb()
     const result = db.prepare(`
       INSERT INTO exam_results (user_id, exam_id, title, score_points, total_points, correct_count, graded_count, passing_score, elapsed_ms, state_json, exam_json)
@@ -91,7 +102,7 @@ router.post('/', requireAuth, (req, res) => {
       gradedCount,
       passingScore ?? 60,
       elapsedMs ?? 0,
-      JSON.stringify(state),
+      JSON.stringify(normalizedState),
       JSON.stringify(exam),
     )