Round 20: Student Portal, District Management, userId field, styling enhancements, bug fixes

- Added userId field to Student model with User relation
- Created Student Portal view with 6 tabs (competencies, goals, achievements, schedule, homework, feedback)
- Created StudentGoal model + CRUD API with role-based access
- Created District Management view with CRUD, analytics, school assignment
- Enhanced auth page: animated gradient, floating particles, glassmorphism, staggered entrance
- Enhanced dashboard: time-based greeting, animated stat cards, class overview, school branding
- Enhanced student portal: hero section, circular progress, streak counter, celebration particles
- Fixed student-goals API 403 for STUDENT role (name-matching fallback for legacy data)
- Added userId filter to students API with OR fallback
- Added nav.student-portal i18n key
- 100+ new i18n keys in DE and EN
- All lint checks pass

src/lib/store.ts

@@ -29,7 +29,9 @@ export type ViewName =
   | 'portfolio'
   | 'timetable'
   | 'resources'
-  | 'competitions';
+  | 'competitions'
+  | 'districts'
+  | 'student-portal';
 
 export interface CurrentUser {
   id: string;