Extend LE *.unkin.net wildcard to arrstack + authentik (reflect into gitea) (#418)

## Why

#417 stood up the central Let's Encrypt `*.unkin.net` wildcard (Certificate `wildcard-unkin-net` in `cert-manager`, secret `wildcard-unkin-net-tls`, emberstack-reflected). This wires the remaining single-label public hosts onto that publicly-trusted leaf instead of the internal Vault-PKI CA.

A `*.unkin.net` wildcard matches **single-label** subdomains only, so cluster hostnames under `*.k8s.syd1.au.unkin.net` are deliberately left on `vault-issuer`.

> Note: PR #417 already merged to `main`, so this is no longer stacked — it targets `main` directly.

## How

- **cert-manager**: reflect `wildcard-unkin-net-tls` into `arrstack`, `authentik`, `gitea` (appended to both reflector namespace lists → `cheeztv,arrstack,authentik,gitea`).
- **arrstack**: repoint the public `arrproxy` gateway listener (`arrstack.unkin.net`) `certificateRefs` → `wildcard-unkin-net-tls`; drop its `cert-manager.io/*` vault-issuer annotations.
- **authentik**: repoint the `identity.unkin.net` https listener → `wildcard-unkin-net-tls`. The `identity.k8s.syd1.au.unkin.net` listeners keep `authentik-tls` (vault-issuer), so the gateway `common-name` is retargeted to that cluster host. `authentik-ldap` gateway untouched.
- **gitea**: secret **reflected only**; `git.unkin.net` cutover deferred (no manifest change), same deferred pattern as fafflix.

## Validation

- `kustomize build` OK for cert-manager / arrstack / authentik / gitea overlays.
- `kubeconform` all valid (0 invalid, 0 errors) across the four overlays.
- Verified no `*.k8s.syd1.au.unkin.net` listener lost its vault-issuer wiring.

Reviewed-on: #418
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>

apps/base/authentik/httproute.yaml

@@ -7,16 +7,11 @@ metadata:
 spec:
   hostnames:
     - identity.unkin.net
-    - identity.k8s.syd1.au.unkin.net
   parentRefs:
     - group: gateway.networking.k8s.io
       kind: Gateway
       name: authentik
       sectionName: http
-    - group: gateway.networking.k8s.io
-      kind: Gateway
-      name: authentik
-      sectionName: http-internal
   rules:
     - filters:
         - type: RequestRedirect
@@ -36,16 +31,60 @@ metadata:
 spec:
   hostnames:
     - identity.unkin.net
-    - identity.k8s.syd1.au.unkin.net
   parentRefs:
     - group: gateway.networking.k8s.io
       kind: Gateway
       name: authentik
       sectionName: https
-    - group: gateway.networking.k8s.io
-      kind: Gateway
-      name: authentik
-      sectionName: https-internal
+  rules:
+    - backendRefs:
+        - group: ""
+          kind: Service
+          name: authentik-server
+          port: 80
+          weight: 1
+      matches:
+        - path:
+            type: PathPrefix
+            value: /
+---
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: authentik-http-redirect-internal
+  namespace: authentik
+spec:
+  hostnames:
+    - identity.k8s.syd1.au.unkin.net
+  parentRefs:
+    - group: gateway.networking.k8s.io
+      kind: Gateway
+      name: authentik-internal
+      sectionName: http
+  rules:
+    - filters:
+        - type: RequestRedirect
+          requestRedirect:
+            scheme: https
+            statusCode: 301
+      matches:
+        - path:
+            type: PathPrefix
+            value: /
+---
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: authentik-internal
+  namespace: authentik
+spec:
+  hostnames:
+    - identity.k8s.syd1.au.unkin.net
+  parentRefs:
+    - group: gateway.networking.k8s.io
+      kind: Gateway
+      name: authentik-internal
+      sectionName: https
   rules:
     - backendRefs:
         - group: ""