feat: warn on the dashboard when a swarm check is overdue

Schwarmkontrolle already captures nextCheckDate per check, but it was
only ever visible by opening that one colony's tab. During swarm
season a missed follow-up check can mean losing half the colony, so
this now surfaces as a dashboard alert (OVERDUE_SWARM_CHECK) like
overdue tasks already do - only the most recent check per colony is
considered, so a completed follow-up clears the warning.

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

ApiCore-Frontend/src/lib/dashboard/types.ts

@@ -7,7 +7,11 @@ export interface DashboardSummary {
   stockItemsLowCount: number;
 }
 
-export type DashboardAlertType = "OVERDUE_TASK" | "COLONY_ATTENTION" | "LOW_STOCK";
+export type DashboardAlertType =
+  | "OVERDUE_TASK"
+  | "COLONY_ATTENTION"
+  | "LOW_STOCK"
+  | "OVERDUE_SWARM_CHECK";
 
 export interface DashboardAlert {
   type: DashboardAlertType;