feat: fold traefik into the service widget type, remove the dedicated one

Traefik gets the same treatment as the other six services now instead
of a bespoke widget type: docker health merged with a single "Routes"
stat, via the same internal container-to-container API call
(http://traefik:8080/api/http/routers) it already used. No auth
needed, same as before.

Deleted lib/collectors/traefik.ts, lib/types/traefik-result.ts, and
components/widgets/traefik/ entirely - the generic service Widget.tsx
and ServiceWidgetResult shape cover it with zero new component code.

lib/collectors/services/base-url.ts

@@ -7,6 +7,7 @@ const SERVICE_PORTS: Record<ServiceWidget["service"], number> = {
   n8n: 5678,
   umami: 3000,
   headscale: 8080,
+  traefik: 8080,
 };
 
 export function serviceBaseUrl(widget: ServiceWidget): string {

lib/collectors/services/traefik.ts

@@ -0,0 +1,17 @@
+import type { TraefikServiceWidget } from "@/lib/config/schema";
+import type { ServiceStat } from "@/lib/types/service-result";
+import { serviceBaseUrl } from "./base-url";
+
+interface RawRouter {
+  status: string;
+}
+
+export async function collectTraefikStat(widget: TraefikServiceWidget): Promise<{ stats: ServiceStat[] }> {
+  const base = serviceBaseUrl(widget);
+  const response = await fetch(`${base}/api/http/routers`, { signal: AbortSignal.timeout(5_000) });
+  if (!response.ok) {
+    throw new Error(`Traefik API returned ${response.status}`);
+  }
+  const routers = (await response.json()) as RawRouter[];
+  return { stats: [{ label: "Routes", value: String(routers.length) }] };
+}