Split authentik gateway into public wildcard + internal vault-issuer gateways

The single authentik Gateway kept cert-manager.io annotations (vault-issuer,
common-name identity.k8s.syd1.au.unkin.net) while its public identity.unkin.net
https listener referenced the reflector-managed wildcard-unkin-net-tls. The
cert-manager gateway-shim mints a Certificate per distinct listener secretName
from Gateway-level annotations, so it would create a competing vault-issuer
Certificate for wildcard-unkin-net-tls and fight the emberstack reflector over
that secret.

Split into two Gateways mirroring the cheeztv/fafflix convention:
- authentik (public): identity.unkin.net listeners on wildcard-unkin-net-tls,
  no cert-manager annotations, external-dns publishes identity.unkin.net.
- authentik-internal: identity.k8s.syd1.au.unkin.net listeners on authentik-tls
  with the vault-issuer cert-manager annotations, external-dns publishes the
  cluster host. Both target 198.18.200.4.

Update HTTPRoutes to attach each hostname's redirect + app route to the
matching gateway's http/https sections.

apps/base/authentik/gateway.yaml

@@ -1,19 +1,18 @@
 ---
-# The public identity.unkin.net listener terminates TLS with the real Let's
-# Encrypt *.unkin.net wildcard (Certificate wildcard-unkin-net in cert-manager,
-# reflected here as wildcard-unkin-net-tls). The cluster-hostname listeners
-# (identity.k8s.syd1.au.unkin.net) keep the Vault-PKI authentik-tls, whose
-# cert-manager annotations below now key the common-name off that cluster host.
+# Public identity.unkin.net listener. external-dns publishes the A record at the
+# internal LB VIP (198.18.200.4). Public TLS is terminated with the real Let's
+# Encrypt *.unkin.net wildcard, centrally minted once in the cert-manager
+# namespace (Certificate wildcard-unkin-net) and reflected into this namespace
+# by the emberstack reflector as the secret wildcard-unkin-net-tls. No
+# cert-manager annotations here so the gateway-shim does not mint a competing
+# Vault-PKI Certificate for the reflected secret.
 apiVersion: gateway.networking.k8s.io/v1
 kind: Gateway
 metadata:
   labels:
     traefik.io/instance: internal
   annotations:
-    cert-manager.io/cluster-issuer: vault-issuer
-    cert-manager.io/common-name: identity.k8s.syd1.au.unkin.net
-    cert-manager.io/private-key-size: "4096"
-    external-dns.alpha.kubernetes.io/hostname: identity.unkin.net,identity.k8s.syd1.au.unkin.net
+    external-dns.alpha.kubernetes.io/hostname: identity.unkin.net
     external-dns.alpha.kubernetes.io/target: 198.18.200.4
   name: authentik
   namespace: authentik
@@ -40,18 +39,38 @@ spec:
             kind: Secret
             name: wildcard-unkin-net-tls
         mode: Terminate
+---
+# Cluster hostname variant, identity.k8s.syd1.au.unkin.net. Internal Traefik,
+# external-dns at 198.18.200.4. Own leaf from the Vault PKI issuer via the
+# cert-manager gateway-shim; the common-name keys off this cluster host.
+apiVersion: gateway.networking.k8s.io/v1
+kind: Gateway
+metadata:
+  labels:
+    traefik.io/instance: internal
+  annotations:
+    cert-manager.io/cluster-issuer: vault-issuer
+    cert-manager.io/common-name: identity.k8s.syd1.au.unkin.net
+    cert-manager.io/private-key-size: "4096"
+    external-dns.alpha.kubernetes.io/hostname: identity.k8s.syd1.au.unkin.net
+    external-dns.alpha.kubernetes.io/target: 198.18.200.4
+  name: authentik-internal
+  namespace: authentik
+spec:
+  gatewayClassName: traefik-internal
+  listeners:
     - allowedRoutes:
         namespaces:
           from: Same
       hostname: identity.k8s.syd1.au.unkin.net
-      name: http-internal
+      name: http
       port: 80
       protocol: HTTP
     - allowedRoutes:
         namespaces:
           from: Same
       hostname: identity.k8s.syd1.au.unkin.net
-      name: https-internal
+      name: https
       port: 443
       protocol: HTTPS
       tls:

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: ""