feat: Ein-/Auswinterung und Winterverluste je Volk

- WinterCheck per colony, winter and season (autumn/spring), every field
  editable; loss causes limited to the COLOSS monitoring categories.
- Summary per winter and apiary: loss rate lost/wintered, marked
  provisional while colonies are not yet checked in spring - an unchecked
  colony never counts as survived.
- A loss marks the colony deceased only on explicit request, in the same
  transaction and audited.
- Permissions winter-checks:read/create/update granted by migration to
  beekeeper and staff roles; winter checks included in backups.
- Page "Überwinterung": next action first, one button per row until the
  colony is wintered, German number format.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

ApiCore-Backend/src/app.module.ts

@@ -40,6 +40,7 @@ import { ImportModule } from './import/import.module';
 import { PublicModule } from './public/public.module';
 import { TaskTemplatesModule } from './task-templates/task-templates.module';
 import { SwarmControlModule } from './swarm-control/swarm-control.module';
+import { WinterChecksModule } from './winter-checks/winter-checks.module';
 import { WeatherModule } from './weather/weather.module';
 import { ProfileModule } from './profile/profile.module';
 import { SiteSettingsModule } from './site-settings/site-settings.module';
@@ -95,6 +96,7 @@ import { IdempotencyCleanupService } from './common/idempotency/idempotency-clea
     PublicModule,
     TaskTemplatesModule,
     SwarmControlModule,
+    WinterChecksModule,
     WeatherModule,
     ProfileModule,
     SiteSettingsModule,