Revert "fix: remove traefik-dashboard IngressRoute (conflicts with k3s built-in Traefik Helm chart)"

This reverts commit a2d0682168.

bootstrap/traefik-routes/manifests/traefik-dashboard.yaml

@@ -0,0 +1,19 @@
+# Traefik Dashboard IngressRoute
+apiVersion: traefik.io/v1alpha1
+kind: IngressRoute
+metadata:
+  name: traefik-dashboard
+  namespace: kube-system
+spec:
+  entryPoints:
+    - websecure
+  routes:
+    - match: HostRegexp(`traefik.k3s\..+\.local`) && (PathPrefix(`/dashboard`) || PathPrefix(`/api`))
+      kind: Rule
+      middlewares:
+        - name: sslheader
+          namespace: kube-system
+      services:
+        - name: api@internal
+          kind: TraefikService
+  tls: {}