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.

components/widgets/registry.ts

@@ -6,7 +6,6 @@ import { DockerWidget } from "./docker/Widget";
 import { DatabaseWidget } from "./database/Widget";
 import { SystemWidget } from "./system/Widget";
 import { HttpWidget } from "./http/Widget";
-import { TraefikWidget } from "./traefik/Widget";
 import { ServiceWidget } from "./service/Widget";
 
 type WidgetComponent<T extends Widget["type"]> = ComponentType<{
@@ -21,6 +20,5 @@ export const widgetRegistry: { [K in Widget["type"]]: WidgetComponent<K> } = {
   database: DatabaseWidget,
   system: SystemWidget,
   http: HttpWidget,
-  traefik: TraefikWidget,
   service: ServiceWidget,
 };