feat: T4 wave 3 - notifications per user, suggestions API, varroa bands, split/queen events

- Schema III: per-user notifications (broadcast fan-out migration,
  category, link, requiredPermissions filter), notification preferences
  and settings endpoints, calendar withdrawal switch, occupiedFrames
- Suggestions API: list/summary with permission visibility and paging,
  accept/dismiss/reopen incl. bulk, SuggestionView on all responses
- Varroa traffic light by season and method, young colonies, treatment
  effect window, sample-based percentage; shared withdrawal-window helper
  on Berlin calendar days; GET /varroa-measurements/thresholds
- ColonySplit and QueenAssigned domain events with calendar and webhook
  handlers
- Outbox claims compare against now() rounded to timestamp(3); fixes the
  flaky e2e claims of rows written with SQL now()

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

ApiCore-Backend/src/varroa/dto/create-varroa-measurement.dto.ts

@@ -6,6 +6,7 @@ import {
   IsNumber,
   IsOptional,
   IsString,
+  Max,
   Min,
 } from 'class-validator';
 import { VarroaMethod } from '../../../generated/prisma';
@@ -35,6 +36,18 @@ export class CreateVarroaMeasurementDto {
   @Min(0)
   miteCount?: number;
 
+  @ApiPropertyOptional({
+    description:
+      'Sample size in bees (powdered sugar, washing); the percentage is mites / sample * 100.',
+    minimum: 1,
+    maximum: 2000,
+  })
+  @IsOptional()
+  @IsInt()
+  @Min(1)
+  @Max(2000)
+  sampleBees?: number;
+
   @ApiPropertyOptional()
   @IsOptional()
   @IsNumber()

ApiCore-Backend/src/varroa/dto/varroa-thresholds.query.ts

@@ -0,0 +1,29 @@
+import { ApiPropertyOptional } from '@nestjs/swagger';
+import { IsOptional, IsString, Matches, MaxLength } from 'class-validator';
+
+const MAX_ID_LENGTH = 64;
+const DAY_PATTERN = /^\d{4}-\d{2}-\d{2}$/;
+
+/**
+ * GET /varroa-measurements/thresholds. The date is only shape-checked here;
+ * an impossible day (2026-02-30) is rejected by the service.
+ */
+export class VarroaThresholdsQuery {
+  @ApiPropertyOptional({
+    description: 'Volk, für dessen Typ die Bänder gelten',
+  })
+  @IsOptional()
+  @IsString()
+  @MaxLength(MAX_ID_LENGTH)
+  @Matches(/^[A-Za-z0-9_-]+$/, { message: 'colonyId ist ungültig' })
+  colonyId?: string;
+
+  @ApiPropertyOptional({
+    description: 'Messtag (JJJJ-MM-TT), ohne Angabe heute (Berlin)',
+    example: '2026-08-10',
+  })
+  @IsOptional()
+  @IsString()
+  @Matches(DAY_PATTERN, { message: 'date muss ein Tag (JJJJ-MM-TT) sein' })
+  date?: string;
+}