feat(api): expose unifiOs widget summary query through tRPC router and request handler

Create unifiOs request handler with 60s cache and stale-on-error fallback, and tRPC router exposing clientApi.widget.unifiOs.summary query. Include minimal widget stub for type system.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

packages/request-handler/src/unifi-os.ts

@@ -0,0 +1,16 @@
+import { createIntegrationAsync } from "@homarr/integrations";
+import type { UnifiOsSummary } from "@homarr/integrations/types";
+
+import { createIntegrationRequestHandler } from "./lib/integration-request-handler";
+
+export const unifiOsRequestHandler = createIntegrationRequestHandler<UnifiOsSummary, "unifiOs", Record<string, never>>({
+  async requestAsync(integration, _input) {
+    const integrationInstance = await createIntegrationAsync(integration);
+    return await integrationInstance.getUnifiOsSummaryAsync();
+  },
+  cacheTtlMs: 60 * 1000,
+  // Une console momentanément injoignable doit afficher la dernière valeur connue
+  // plutôt qu'une tuile d'erreur ; le widget signale la péremption.
+  fallbackToStaleOnError: true,
+  staleIfErrorTtlMs: 10 * 60 * 1000,
+});