Consolidate Harbor TLS certificates into single multi-SAN certificate

- Merge harbor-alt-tls into harbor-tls certificate
- Single certificate now covers both DNS names:
  - the-seas.local.mk-labs.cloud (EPCOT theme)
  - harbor.local.mk-labs.cloud (functional name)
- Remove duplicate certificate-alt.yaml
- Reduces cert-manager overhead and simplifies certificate management

cluster/platform/harbor/certificate-alt.yaml

@@ -1,16 +0,0 @@
-# ------------------------------------------------------------------------------
-# Certificate — Harbor Alternate TLS Certificate (staging until stable)
-# Alternate DNS: harbor.local.mk-labs.cloud
-# ------------------------------------------------------------------------------
-apiVersion: cert-manager.io/v1
-kind: Certificate
-metadata:
-  name: harbor-alt-tls
-  namespace: harbor
-spec:
-  secretName: harbor-alt-tls
-  issuerRef:
-    name: letsencrypt-staging
-    kind: ClusterIssuer
-  dnsNames:
-    - harbor.local.mk-labs.cloud

cluster/platform/harbor/certificate.yaml

@@ -1,6 +1,6 @@
 # ------------------------------------------------------------------------------
 # Certificate — Harbor TLS Certificate (staging until stable)
-# Primary DNS: the-seas.local.mk-labs.cloud
+# DNS Names: the-seas.local.mk-labs.cloud, harbor.local.mk-labs.cloud
 # ------------------------------------------------------------------------------
 apiVersion: cert-manager.io/v1
 kind: Certificate
@@ -14,3 +14,4 @@ spec:
     kind: ClusterIssuer
   dnsNames:
     - the-seas.local.mk-labs.cloud
+    - harbor.local.mk-labs.cloud