Retire bao.coulomb.social callbacks from the KeyCape openbao-admin client

The name was retired on 2026-09-15. Remove both public UI callbacks from
the code-defined client (openbao-client-config.py, create-secrets.sh), stop
probing them in verify-openbao-client.sh, and fail verification in
openbao-client-config.py and verify-t07.sh if either is registered again.
The CLI and operator-tunneled 127.0.0.1:18200 callbacks remain.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 299762@bnt-lap001
Assistant-Session: d3d3cea1-869c-44f1-be2a-3d6d3550e72e

sso-mfa/k8s/keycape/create-secrets.sh

@@ -140,8 +140,6 @@ clients:
       - "http://localhost:8250/oidc/callback"
       - "http://127.0.0.1:8250/oidc/callback"
       - "http://127.0.0.1:18200/ui/vault/auth/netkingdom/oidc/callback"
-      - "https://bao.coulomb.social/ui/vault/auth/netkingdom/oidc/callback"
-      - "https://bao.coulomb.social/ui/vault/auth/keycape/oidc/callback"
     allowedScopes: ["openid", "profile", "email", "groups"]
     grantTypes: ["authorization_code"]
     clientType: "public"