fix: create question row if missing when saving classification

The update_single endpoint now checks if a questions row exists for
the image_id, and creates one if it doesn't. This fixes the issue
where manual classifications weren't being saved when the question
row was missing.

Co-Authored-By: Claude (claude-opus-4-5-thinking) <noreply@anthropic.com>

routes/questions.py

@@ -310,13 +310,30 @@ def update_question_classification_single():
     if not image_id: return jsonify({'error': 'Image ID is required'}), 400
     try:
         conn = get_db_connection()
-        owner = conn.execute("SELECT s.user_id FROM images i JOIN sessions s ON i.session_id = s.id WHERE i.id = ?", (image_id,)).fetchone()
-        if not owner or owner['user_id'] != current_user.id:
+        # Get image info and verify ownership
+        img_info = conn.execute("""
+            SELECT i.session_id, s.user_id FROM images i
+            JOIN sessions s ON i.session_id = s.id WHERE i.id = ?
+        """, (image_id,)).fetchone()
+        if not img_info or img_info['user_id'] != current_user.id:
             conn.close(); return jsonify({'error': 'Unauthorized'}), 403
-        conn.execute('UPDATE questions SET subject = ?, chapter = ? WHERE image_id = ?', (subject, chapter, image_id))
+
+        # Check if question row exists
+        existing = conn.execute('SELECT id FROM questions WHERE image_id = ?', (image_id,)).fetchone()
+        if existing:
+            conn.execute('UPDATE questions SET subject = ?, chapter = ? WHERE image_id = ?', (subject, chapter, image_id))
+        else:
+            # Create question row if it doesn't exist
+            conn.execute('''
+                INSERT INTO questions (session_id, image_id, question_number, subject, chapter, status)
+                VALUES (?, ?, '', ?, ?, 'unattempted')
+            ''', (img_info['session_id'], image_id, subject, chapter))
+
         conn.commit(); conn.close()
         return jsonify({'success': True})
-    except Exception as e: return jsonify({'error': str(e)}), 500
+    except Exception as e:
+        current_app.logger.error(f"Error updating classification: {e}")
+        return jsonify({'error': str(e)}), 500
 
 
 @main_bp.route('/question_entry_v2/<session_id>')