Stabilize credential-change test suite (RAILIANCE-WP-0014)

Five failures in full credential test discovery, none of them broker
regressions:

- CCR-2026-0009 referenced a policy file that was never added, and used a
  schema-invalid access_frontdoor.readiness value. Add the least-privilege
  workload-kv-read-qonto-assistant.hcl (read-only on tenants/binky/qonto-api)
  and set readiness to pending-review. The lane stays proposed and
  non-resolvable.

- Three refusal tests used the live CCR-2026-0002 file as their "unapproved
  CCR" fixture. That lane is now approved, applied and active, so the gates
  correctly permitted it and the tests failed; applier-apply then walked into
  its interactive confirmation prompt and raised EOFError under a
  non-interactive runner. Add an unapproved_ccr() helper that materializes a
  normalized temp copy so approval state is no longer read off a mutable
  production artifact.

- The approve/unconfirmed-claim test demoted an active CCR to approved while
  leaving resolvable=true, tripping a correct validation rule. Build it from
  the same helper.

No gate, blocker, validation rule, or grant semantic was changed. Verified:
credential discovery 52/52 and full discovery 61/61 pass non-interactively,
make credential-change-validate passes all nine CCRs, the grant catalog
validates, and both audit-core openbao-database-credential grants retain
exec-env-only delivery and revoke-on-exec-exit.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

credential-change-requests/CCR-2026-0009-qonto-assistant-workload-kv-read.yaml

@@ -59,7 +59,7 @@ access_frontdoor:
   selector: qonto-assistant workload Qonto API key
   command: warden access qonto-assistant-workload-kv --fetch API_KEY,API_USER
   resolvable: false
-  readiness: proposed
+  readiness: pending-review
 delivery:
   surface: external-secrets
   target: >-