ci: retrigger apply for pending Keel enrollment (~58 stacks)

Bulk enrollment commit 8f4b1956 had its CI pipeline #689 killed before
terragrunt apply ran. The enrollment label + V2 lifecycle changes are
in master but never reached the cluster. Appending a one-line marker
to each pending stack's main.tf so Woodpecker's diff-detection picks
them up and applies them serially.

Idempotent — re-applying a stack whose state already matches is a no-op.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

stacks/webhook_handler/main.tf

@@ -311,3 +311,5 @@ resource "kubernetes_manifest" "external_secret" {
   }
   depends_on = [kubernetes_namespace.webhook-handler]
 }
+
+# CI retrigger 2026-05-16T13:42:57+00:00 — bulk enrollment apply (pipeline #689 killed)