feat: Update enrollment last accessed timestamp on course content access and correct k6 test comment typo.

Backend/src/services/CoursesStudent.service.ts

@@ -340,6 +340,17 @@ export class CoursesStudentService {
                 throw new ForbiddenError('You are not enrolled in this course');
             }
 
+            // Update last_accessed_at (fire-and-forget — ไม่ block response)
+            prisma.enrollment.update({
+                where: {
+                    unique_enrollment: {
+                        user_id: decoded.id,
+                        course_id,
+                    },
+                },
+                data: { last_accessed_at: new Date() },
+            }).catch(err => logger.warn(`Failed to update last_accessed_at: ${err}`));
+
             // Get all lesson progress for this user and course
             const lessonIds = course.chapters.flatMap(ch => ch.lessons.map(l => l.id));
             const lessonProgress = await prisma.lessonProgress.findMany({

Backend/tests/k6/login-load-test.js

@@ -31,7 +31,7 @@ export const options = {
     thresholds: {
         http_req_duration: ['p(95)<2000'],  // 95% of requests < 2s
         errors: ['rate<0.1'],               // Error rate < 10%
-        login_duration: ['p(95)<2000'],     // 95% of logins < 2s
+        login_duration: ['p(95)<2000'],     // 95% pof logins < 2s
     },
 };