feat(forte-drop): wildcard cert *.drop.forteapps.net for subdomain-per-drop

forte_drop is moving to per-slug subdomains: forte-login drops served at
<slug>.drop.forteapps.net (sidecar-gated), public/password drops at
drop.forteapps.net/shared/<slug>. That needs a wildcard TLS cert.

- letsencrypt-issuer.yaml: add '*.drop.forteapps.net' + 'drop.forteapps.net' to
  the dns01 azureDNS solver selector in BOTH issuers. The existing '*.forteapps.net'
  selector only matches single-label children, so it does NOT cover the two-label
  '*.drop.forteapps.net' — without this the wildcard challenge has no matching solver
  and issuance fails. SP already has zone-level rights on forteapps.net.
- new Certificate wildcard-drop-forteapps-net in the forte-drop namespace -> secret
  wildcard-drop-forteapps-net-tls (dnsNames *.drop + apex). Issued in-namespace so the
  app's Traefik IngressRoute can reference it directly (the secret-cloner can't help:
  generateExisting:false + forte-drop ns already exists). Added to the overlay
  kustomization so ArgoCD manages it (the Application is prune+selfHeal).

This is the SINGLE issuer of that secret. The forte-helm chart must reference it
verbatim and must NOT create its own Certificate into the same secret.

Depends on: DNS *.drop.forteapps.net resolving + ACME TXT in the flat forteapps.net
zone (no delegated drop. child zone). Do NOT merge until that's confirmed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/overlays/upc-dev/forte-drop/kustomization.yaml

@@ -5,3 +5,4 @@ resources:
 - keycloak-client-forte-drop.yaml
 - forte-drop-pdb.yaml
 - forte-drop-secrets-sealed.yaml
+- wildcard-drop-tls-certificate.yaml

apps/overlays/upc-dev/forte-drop/wildcard-drop-tls-certificate.yaml

@@ -0,0 +1,34 @@
+---
+# Wildcard TLS cert for the per-slug drop subdomains: <slug>.drop.forteapps.net.
+# forte_drop serves forte-login drops on their own subdomain (gated by the auth
+# sidecar), so each drop needs a valid cert for *.drop.forteapps.net.
+#
+# Issued DIRECTLY into the forte-drop namespace (not cert-manager) so the app's
+# Traefik IngressRoute — which must reference a TLS secret in its OWN namespace —
+# can use it without cross-namespace cloning. The secret-cloner Kyverno policy
+# can't help here: it only clones on NEW namespace creation (generateExisting:false)
+# and forte-drop already exists.
+#
+# This is the SINGLE issuer of secret `wildcard-drop-forteapps-net-tls`. The
+# forte-helm chart must reference this secret VERBATIM and must NOT also create a
+# Certificate into the same secret (else cert-manager thrashes). The dns01 solver
+# in letsencrypt-prod is authorized for these names via its selector.dnsNames.
+apiVersion: cert-manager.io/v1
+kind: Certificate
+metadata:
+  name: wildcard-drop-forteapps-net
+  namespace: forte-drop
+spec:
+  secretName: wildcard-drop-forteapps-net-tls
+  issuerRef:
+    name: letsencrypt-prod
+    kind: ClusterIssuer
+  dnsNames:
+  - '*.drop.forteapps.net' # per-slug forte drop subdomains
+  - 'drop.forteapps.net'   # apex (admin + /shared public drops)
+  duration: 2160h0m0s # 90 days
+  renewBefore: 720h0m0s # renew 30 days before expiry
+  privateKey:
+    algorithm: RSA
+    encoding: PKCS1
+    size: 4096

cluster-resources/letsencrypt-issuer.yaml

@@ -25,6 +25,10 @@ spec:
             key: client-secret
       selector:
         dnsNames:
+        # *.forteapps.net only matches single-label children, NOT *.drop.forteapps.net,
+        # so the per-drop subdomain wildcard needs its own selector entry.
+        - '*.drop.forteapps.net'
+        - 'drop.forteapps.net'
         - '*.forteapps.net'
         - 'forteapps.net'
     # HTTP-01 fallback for non-wildcard certificates
@@ -59,6 +63,10 @@ spec:
             key: client-secret
       selector:
         dnsNames:
+        # *.forteapps.net only matches single-label children, NOT *.drop.forteapps.net,
+        # so the per-drop subdomain wildcard needs its own selector entry.
+        - '*.drop.forteapps.net'
+        - 'drop.forteapps.net'
         - '*.forteapps.net'
         - 'forteapps.net'
     # HTTP-01 fallback for non-wildcard certificates