feat: sync calendar entries to a Microsoft 365 group calendar

Adds a one-way push (ApiCore -> M365) of Aufgaben/Durchsichten/
Behandlungen/Fütterungen/Ernten/Königinnen-Zuordnungen into the calendar
of a Microsoft 365 group, via the Graph API.

- CalendarSyncModule (app-only client-credentials Graph auth, separate
  from the interactive SSO app registration; new env vars
  M365_CALENDAR_TENANT_ID/_CLIENT_ID/_CLIENT_SECRET).
- Outbox + minute-interval cron worker (CalendarSyncOutboxEntry) instead
  of a synchronous push, since Graph calls are too slow/flaky to block a
  domain create request on; failed syncs retry up to 5 times.
- Per-source-type toggle plus a group-ID field, configurable in
  Verwaltung > Automatisierung > Kalender-Sync (Verwaltung > Backup, an
  env var still wins on those fields where one applies to related config).
- Hooked into Tasks/Inspections/Treatments/Feedings/Harvests/Queens at
  their existing create (and Task update/complete) points; entries render
  as all-day Graph events to avoid timezone ambiguity.
- Documents the design decision in ARCHITECTURE.md (Annahme 9), since
  this is a net-new capability the lastenheft doesn't scope.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

ApiCore-Frontend/src/lib/calendar-sync/api.ts

@@ -0,0 +1,29 @@
+import { apiFetch } from "@/lib/auth/api-client";
+import {
+  CalendarSyncSettings,
+  CalendarSyncStatus,
+  UpdateCalendarSyncSettingsInput,
+} from "./types";
+
+export function getCalendarSyncSettings(): Promise<CalendarSyncSettings> {
+  return apiFetch<CalendarSyncSettings>("/calendar/sync/settings");
+}
+
+export function updateCalendarSyncSettings(
+  input: UpdateCalendarSyncSettingsInput,
+): Promise<CalendarSyncSettings> {
+  return apiFetch<CalendarSyncSettings>("/calendar/sync/settings", {
+    method: "PATCH",
+    body: JSON.stringify(input),
+  });
+}
+
+export function getCalendarSyncStatus(): Promise<CalendarSyncStatus> {
+  return apiFetch<CalendarSyncStatus>("/calendar/sync/status");
+}
+
+export function runCalendarSyncNow(): Promise<CalendarSyncStatus> {
+  return apiFetch<CalendarSyncStatus>("/calendar/sync/run-now", {
+    method: "POST",
+  });
+}

ApiCore-Frontend/src/lib/calendar-sync/types.ts

@@ -0,0 +1,32 @@
+export interface CalendarSyncSettings {
+  id: string;
+  enabled: boolean;
+  groupId: string | null;
+  syncTask: boolean;
+  syncInspection: boolean;
+  syncTreatment: boolean;
+  syncFeeding: boolean;
+  syncHarvest: boolean;
+  syncQueenAssignment: boolean;
+  updatedAt: string;
+}
+
+export interface UpdateCalendarSyncSettingsInput {
+  enabled?: boolean;
+  groupId?: string;
+  syncTask?: boolean;
+  syncInspection?: boolean;
+  syncTreatment?: boolean;
+  syncFeeding?: boolean;
+  syncHarvest?: boolean;
+  syncQueenAssignment?: boolean;
+}
+
+export interface CalendarSyncStatus {
+  configured: boolean;
+  enabled: boolean;
+  groupId: string | null;
+  pendingCount: number;
+  failedCount: number;
+  syncedCount: number;
+}