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-Backend/package.json

@@ -92,7 +92,7 @@
       "^.+\\.(t|j)s$": "ts-jest"
     },
     "transformIgnorePatterns": [
-      "node_modules/(?!(otplib|@otplib|@scure|@noble|openid-client|oauth4webapi|jose)/)"
+      "node_modules/(?!(otplib|@otplib|@scure|@noble|openid-client|oauth4webapi|jose|@nestjs/schedule|cron)/)"
     ],
     "collectCoverageFrom": [
       "**/*.(t|j)s"