Give the reuse landing catch-all its own Ingress and an explicit priority

/health returned nginx 404 through the ingress while the service answered 200
in-cluster. The ingress rule was correct on paper — /health Exact ->
reuse-surface:8000 alongside / Prefix -> reuse-surface-landing:8080 — but
Traefik derives router priority from the length of the generated rule string,
and Path(`/health`) and PathPrefix(`/`) are both 15 characters. The tie broke
toward the landing page. PathPrefix(`/v1`) is longer, which is why /v1 worked
and the fault looked like a /health-only bug.

traefik.ingress.kubernetes.io/router.priority applies per Ingress, not per
path, so the catch-all moves into its own Ingress with priority 1. Every API
route now outranks it regardless of rule length.

This is not cosmetic: make reuse-smoke curls /health and false-negatives on an
otherwise healthy release.

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

charts/reuse-surface/values.yaml

@@ -35,6 +35,11 @@ landing:
   service:
     port: 8080
     targetPort: 8080
+  ingress:
+    # Explicit Traefik router priority for the landing catch-all. Traefik
+    # otherwise derives priority from rule-string length, where PathPrefix(`/`)
+    # ties with Path(`/health`) and can win. Keep this below every API route.
+    priority: 1
   noindex: true
   title: "Railiance service endpoint"
   eyebrow: "Railiance S5"