authentik: serve LDAP via an outpost behind the internal gateway

Adds the LDAP outpost deployment and routes ports 389 and 636 on
gateway-internal to it. 636 is a TLS listener in Terminate mode so
cert-manager renews the LDAPS certificate automatically, and both
listeners forward to the outpost's plaintext 3389.

allowedRoutes.kinds is set explicitly on both listeners: a TCP listener
permits no route kinds by default and a TLS listener defaults to
TLSRoute, so the TCPRoute would not attach otherwise.

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

applications/authentik/ldap/tcproute.yaml

@@ -0,0 +1,22 @@
+apiVersion: gateway.networking.k8s.io/v1alpha2
+kind: TCPRoute
+metadata:
+  name: authentik-ldap
+  namespace: authentik
+spec:
+  parentRefs:
+    - group: gateway.networking.k8s.io
+      kind: Gateway
+      name: gateway-internal
+      namespace: envoy-gateway
+      sectionName: authentik-ldap
+    - group: gateway.networking.k8s.io
+      kind: Gateway
+      name: gateway-internal
+      namespace: envoy-gateway
+      sectionName: authentik-ldaps
+  rules:
+    # The gateway terminates TLS on 636, so both listeners hit the plaintext port
+    - backendRefs:
+        - name: authentik-ldap
+          port: 3389