- Require JWT_SECRET env var (fatal exit if missing)
- Add helmet middleware with custom CSP
- Cookie Secure flag when NODE_ENV=production
- requireAuth re-verifies user.status from DB on every request
- class_events DELETE restricted to creator or admin
- Rate limit /register (5/hr) and PUT /me/password (5/15min)
- Password minimum 6 to 8 chars
- crudRoutes truncates strings to 1000 chars
- Remove application/octet-stream from allowed upload MIMEs
- Teacher registration requires subject selection; account starts pending
- Admin approves/rejects via existing admin panel
- Teacher panel (Materialien, Ankündigungen, Prüfungen, Noten) visible only to approved teachers
- Students see class materials and announcements via sidebar overlays
- Teachers can assign grades to students (scoped to own subject)
- New tables: teacher_materials, teacher_announcements, teacher_exams, teacher_assigned_grades
- subject column added to users; included in JWT and /api/me
- requireTeacher middleware fetches fresh status+subject from DB on every request
- Login hint: username is the part of the school email before the @