Expose VictoriaLogs UI at vlogs.unkin.net behind oauth2-proxy (#498)

The vlselect query UI is only reachable in-cluster, so every log search needs a port-forward. Publish it at vlogs.unkin.net behind oauth2-proxy on the external (DMZ) Traefik.

- Add `apps/base/logging/vlogs`: external Gateway, http->https redirect and main HTTPRoute
- Terminate TLS with the reflected Let's Encrypt `*.unkin.net` wildcard; reflect it into `logging`
- Publish the `vlogs` A record at the DMZ gateway VIP from the bind-operator `unkin.net` zone
- Route all traffic through the `vlogs-oauth2` Service, upstreaming to `vlselect-logs:9471`
- Gate on the Authentik `vlogs` application, group `akP-vlogs-admin`
- Read OIDC credentials from `kv/kubernetes/namespace/logging/default/vlogs-oauth-credentials`

Depends on unkin/terraform-authentik#40.

Reviewed-on: #498
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>

apps/base/bind-internal/authoritative/records.yaml

@@ -162,3 +162,18 @@ spec:
     # traefik-EXTERNAL (DMZ) gateway VIP; the watchstate-external Gateway serves
     # the watchstate.unkin.net front door (oauth2-proxy) there.
     - 198.18.199.0
+---
+apiVersion: bind.unkin.net/v1alpha1
+kind: DNSRecord
+metadata:
+  name: vlogs-dns-internal
+  namespace: bind-internal
+spec:
+  zoneRef: unkin-net
+  name: vlogs
+  type: A
+  ttl: 600
+  values:
+    # traefik-EXTERNAL (DMZ) gateway VIP; the vlogs-external Gateway serves the
+    # vlogs.unkin.net front door (oauth2-proxy) there.
+    - 198.18.199.0