Phase 9b: Schul-Events CRUD + Schuljahres-Rollover

Backend (school-service):
  - calendar_events.go — Create/List/Delete on cal_school_event with
    UUID[] handling for affected_class_ids. Default lead-days [7,1]
    if caller omits the array.
  - calendar_rollover.go — single-transaction promotion: graduating
    classes (grade >= 13) get deleted first so the +1 update doesn't
    bump them to invalid grade 14. defaultSchoolYearDates() picks the
    next Aug-Jul pair when the caller doesn't specify.
  - Handlers + routes: GET/POST /calendar/events,
    DELETE /calendar/events/:id, POST /calendar/school-year-rollover.

Frontend (studio-v2):
  - EventModal: form with Title / Typ / Datum/Zeit / unterrichtsfrei /
    Beschreibung / Sichtbarkeit + Notification-Checkboxen. Per-Type
    Farb-Mapping in types.ts.
  - DayDetail: Modal das beim Klick auf einen Kalender-Tag aufgeht und
    Feiertage + Schulferien + Schul-Events fuer diesen Tag listet,
    inkl. Loeschen-Button pro Event.
  - RolloverWizard: zwei-Schritt-Dialog mit Datums-Auswahl + Tipp-
    Bestaetigung ("SCHULJAHR WECHSELN") gegen versehentliche Auslo-
    sung, danach Ergebnis-Card mit promoted/graduated-Counts.
  - MonthView gewinnt onDayClick + onAddEvent + onRollover Props,
    rendert farb-codierte Punkte fuer School-Events am Tagesrand.
  - Page laed Events parallel mit Holidays und reicht alle Handler
    nach unten.

Tests:
  - Go: 3 neue Tests fuer defaultSchoolYearDates + parseClassIDs.
    Validator-Test fuer CreateSchoolEventRequest existiert bereits.
    80 Subtests gesamt, alle gruen.
  - Playwright: mockCalendarApi gewinnt Routes fuer events GET/POST/
    DELETE und school-year-rollover. 6 neue Tests (EventModal open,
    submit, DayDetail open, Rollover-Trigger, Confirm-Schutz,
    Ergebnis-Anzeige).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

studio-v2/lib/schulkalender/api.ts

@@ -6,6 +6,7 @@
 import { getStundenplanToken } from '@/lib/stundenplan/api'
 import type {
   PublicEvent, SchoolCalendarConfig, UpsertSchoolCalendarConfig,
+  SchoolEvent, CreateSchoolEvent, SchoolYearRolloverResult,
 } from '@/app/schulkalender/types'
 
 async function apiFetch<T>(endpoint: string, options: RequestInit = {}): Promise<T> {
@@ -31,4 +32,21 @@ export const calendarApi = {
   getConfig: () => apiFetch<SchoolCalendarConfig | null>('/calendar/config'),
   upsertConfig: (data: UpsertSchoolCalendarConfig) =>
     apiFetch<SchoolCalendarConfig>('/calendar/config', { method: 'PUT', body: JSON.stringify(data) }),
+
+  // School events
+  listEvents: (from: string, to: string) =>
+    apiFetch<SchoolEvent[]>(`/calendar/events?from=${from}&to=${to}`),
+  createEvent: (data: CreateSchoolEvent) =>
+    apiFetch<SchoolEvent>('/calendar/events', { method: 'POST', body: JSON.stringify(data) }),
+  deleteEvent: (id: string) =>
+    apiFetch<void>(`/calendar/events/${id}`, { method: 'DELETE' }),
+
+  rolloverSchoolYear: (newYearStart?: string, newYearEnd?: string) =>
+    apiFetch<SchoolYearRolloverResult>('/calendar/school-year-rollover', {
+      method: 'POST',
+      body: JSON.stringify({
+        new_year_start: newYearStart,
+        new_year_end: newYearEnd,
+      }),
+    }),
 }