Completed studies: finishing a study keeps access after leaving; certificates always shown; no reminders for finished studies; v2.11.0

- Completion is stored on the user (completedStudySlugs, sticky) when every lesson is done; backfilled at startup
- Lessons, notes, progress, quiz, community and certificate stay open for completed studies after leaving the enrollment
- Dashboard/My Account list completed studies with Review Lessons and certificate access
- Study page shows a completed banner
- Lesson-release reminders, weekly digest and re-engagement emails skip finished studies
- Fix: streak fields (current/longest/last studied) and firstCompletionAt were dropped on every restart when users were loaded
- Tests for completion/access/re-engagement

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

server/routes/study-data.js

@@ -3,13 +3,15 @@ import {
   normalizeStudySlug,
   normalizeLessonSectionId,
   getStudySlugFromNoteId,
-  isStudyUserEnrolled,
+  hasStudyAccess,
   isEnrollableStudySlug,
   getStudyTitleBySlug,
   findStudyUserById,
   getStudyAvatarUrl,
   getStudyCatalog,
   getCommunityDisplayName,
+  getAccessibleStudySlugs,
+  markStudyCompletedIfDone,
 } from '../study-helpers.js'
 import { state } from '../state.js'
 import {
@@ -73,7 +75,8 @@ export function register(app) {
       ok: true,
       studySlug,
       studyTitle: getStudyTitleBySlug(studySlug) || studySlug,
-      enrolledStudySlugs: user.enrolledStudySlugs,
+      enrolledStudySlugs: getAccessibleStudySlugs(user),
+      completedStudySlugs: Array.isArray(user.completedStudySlugs) ? user.completedStudySlugs : [],
     })
   })
 
@@ -96,7 +99,8 @@ export function register(app) {
       ok: true,
       studySlug,
       studyTitle: getStudyTitleBySlug(studySlug) || studySlug,
-      enrolledStudySlugs: user.enrolledStudySlugs,
+      enrolledStudySlugs: getAccessibleStudySlugs(user),
+      completedStudySlugs: Array.isArray(user.completedStudySlugs) ? user.completedStudySlugs : [],
     })
   })
 
@@ -116,7 +120,7 @@ export function register(app) {
     }
     const user = req.studyUser
     const noteStudySlug = getStudySlugFromNoteId(sectionId)
-    if (noteStudySlug && !isStudyUserEnrolled(user, noteStudySlug)) {
+    if (noteStudySlug && !hasStudyAccess(user, noteStudySlug)) {
       res.status(403).json({ message: 'Please enroll in this study to access notes.' })
       return
     }
@@ -136,7 +140,7 @@ export function register(app) {
       return
     }
     const noteStudySlug = getStudySlugFromNoteId(sectionId)
-    if (noteStudySlug && !isStudyUserEnrolled(user, noteStudySlug)) {
+    if (noteStudySlug && !hasStudyAccess(user, noteStudySlug)) {
       res.status(403).json({ message: 'Please enroll in this study to save notes.' })
       return
     }
@@ -170,7 +174,7 @@ export function register(app) {
       return
     }
 
-    if (!isStudyUserEnrolled(user, studySlug)) {
+    if (!hasStudyAccess(user, studySlug)) {
       res.status(403).json({ message: 'Please enroll in this study to view progress.' })
       return
     }
@@ -197,7 +201,7 @@ export function register(app) {
       return
     }
 
-    if (!isStudyUserEnrolled(user, studySlug)) {
+    if (!hasStudyAccess(user, studySlug)) {
       res.status(403).json({ message: 'Please enroll in this study to update progress.' })
       return
     }
@@ -227,8 +231,9 @@ export function register(app) {
       user.firstCompletionAt = new Date().toISOString()
     }
     queueStudyUsersWrite()
+    const justCompleted = markStudyCompletedIfDone(user, studySlug, studyProgress.completedSectionIds)
 
-    res.json({ ok: true, studySlug, completedSectionIds: studyProgress.completedSectionIds })
+    res.json({ ok: true, studySlug, completedSectionIds: studyProgress.completedSectionIds, studyCompleted: justCompleted || undefined })
   })
 
   app.delete('/api/study-progress/:studySlug/:sectionId', requireStudyAuth, async (req, res) => {
@@ -240,7 +245,7 @@ export function register(app) {
       return
     }
 
-    if (!isStudyUserEnrolled(user, studySlug)) {
+    if (!hasStudyAccess(user, studySlug)) {
       res.status(403).json({ message: 'Please enroll in this study to update progress.' })
       return
     }
@@ -267,7 +272,7 @@ export function register(app) {
       return
     }
 
-    if (!isStudyUserEnrolled(user, studySlug)) {
+    if (!hasStudyAccess(user, studySlug)) {
       res.status(403).json({ message: 'Please enroll in this study to view quiz answers.' })
       return
     }
@@ -286,7 +291,7 @@ export function register(app) {
       return
     }
 
-    if (!isStudyUserEnrolled(user, studySlug)) {
+    if (!hasStudyAccess(user, studySlug)) {
       res.status(403).json({ message: 'Please enroll in this study to save quiz answers.' })
       return
     }
@@ -315,7 +320,7 @@ export function register(app) {
     const studySlug = normalizeStudySlug(req.params.studySlug)
     const sectionId = normalizeLessonSectionId(req.params.sectionId)
     if (!studySlug || !sectionId) { res.status(400).json({ message: 'Invalid study slug or section id.' }); return }
-    if (!isStudyUserEnrolled(user, studySlug)) { res.status(403).json({ message: 'Please enroll in this study to bookmark lessons.' }); return }
+    if (!hasStudyAccess(user, studySlug)) { res.status(403).json({ message: 'Please enroll in this study to bookmark lessons.' }); return }
 
     const progress = await loadUserProgress(user.id)
     const studyProgress = progress.byStudy[studySlug] ?? { completedSectionIds: [], bookmarkedSectionIds: [] }
@@ -335,7 +340,7 @@ export function register(app) {
     const studySlug = normalizeStudySlug(req.params.studySlug)
     const sectionId = normalizeLessonSectionId(req.params.sectionId)
     if (!studySlug || !sectionId) { res.status(400).json({ message: 'Invalid study slug or section id.' }); return }
-    if (!isStudyUserEnrolled(user, studySlug)) { res.status(403).json({ message: 'Not enrolled.' }); return }
+    if (!hasStudyAccess(user, studySlug)) { res.status(403).json({ message: 'Not enrolled.' }); return }
 
     const progress = await loadUserProgress(user.id)
     const studyProgress = progress.byStudy[studySlug] ?? { completedSectionIds: [], bookmarkedSectionIds: [] }
@@ -358,7 +363,7 @@ export function register(app) {
       return
     }
 
-    if (!isStudyUserEnrolled(user, studySlug)) {
+    if (!hasStudyAccess(user, studySlug)) {
       res.status(403).json({ message: 'Please enroll in this study to view the community.' })
       return
     }
@@ -403,7 +408,7 @@ export function register(app) {
       return
     }
 
-    if (!isStudyUserEnrolled(user, studySlug)) {
+    if (!hasStudyAccess(user, studySlug)) {
       res.status(403).json({ message: 'Please enroll in this study to post in the community.' })
       return
     }
@@ -445,7 +450,7 @@ export function register(app) {
       return
     }
 
-    if (!isStudyUserEnrolled(user, post.studySlug)) {
+    if (!hasStudyAccess(user, post.studySlug)) {
       res.status(403).json({ message: 'Please enroll in this study to reply in the community.' })
       return
     }
@@ -472,7 +477,7 @@ export function register(app) {
     const postId = typeof req.params.postId === 'string' ? req.params.postId.trim() : ''
     const post = state.studyCommunityPosts.find(item => item.id === postId)
     if (!post) { res.status(404).json({ message: 'Post not found.' }); return }
-    if (!isStudyUserEnrolled(user, post.studySlug)) {
+    if (!hasStudyAccess(user, post.studySlug)) {
       res.status(403).json({ message: 'Please enroll in this study to like posts.' }); return
     }
     if (!Array.isArray(post.likedBy)) post.likedBy = []