fix(dashboard): i18n, a11y, security, and type-safety fixes from PR review

- Use @RequiredArgsConstructor in AuditLogQueryService; remove unused import
- Add 401/403 tests for /activity endpoint
- Add getPulseStats and findContributorsPerDocument integration tests
- Use m.pulse_headline/pulse_you in FamilyPulse; composite avatar keys
- Replace hover:text-accent with hover:text-ink in ActivityFeed (WCAG AA)
- Localise "Alle →" link with feed_show_all key + aria-label
- Gate DropZone behind {#if data.canWrite}
- Export DashboardResumeDTO, DashboardPulseDTO, ActivityFeedItemDTO from api.ts

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/lib/generated/api.ts

@@ -4451,3 +4451,7 @@ export interface operations {
         };
     };
 }
+
+export type DashboardResumeDTO = components['schemas']['DashboardResumeDTO'];
+export type DashboardPulseDTO = components['schemas']['DashboardPulseDTO'];
+export type ActivityFeedItemDTO = components['schemas']['ActivityFeedItemDTO'];