Delete a subscription and every project beneath it

Deprovisions ALL of the subscription's projects (each Keystone project + app-cred) and then removes the subscription itself (issue). Every project's scope projection moves to DEPROVISIONING and one iam.subscription.deprovision Operation is returned (202, PENDING). Safe default: if ANY project beneath the subscription still holds ANY live resource (the same resource count the project delete uses) the delete is refused 409 CONFLICT. The optional body is the cascade consent, the same shape as the project delete's: only acknowledgeAllResourcesDeleted: true PLUS all four categories true is consent; anything less (no body included) takes the safe-default path unchanged. With consent the worker sweeps and verifies every project before deleting it. Imported projects: an IMPORTED project beneath it needs acknowledgeImportedProjectDestruction: true (else 409 IMPORTED_PROJECT_ACK_REQUIRED); inside its protection window a customer cannot destroy it at all (403 IMPORTED_PROJECT_PROTECTED); an import that never completed, or a release in progress, refuses the whole delete (409 IMPORTED_PROJECT_IMPORT_INCOMPLETE / IMPORTED_PROJECT_RELEASE_IN_PROGRESS). Authorization: ANY bearer (API token or service-account key) is refused 403 INTERACTIVE_SESSION_REQUIRED before anything else -- this cascade destroys cloud resources and needs an interactive console session. Then: unreached subscription 404; no SUBSCRIPTION-level owner grant 403 (a project owner is not enough); tenant on non-payment hold 403 TENANT_SUSPENDED. Async & state: 202 + Operation PENDING → RUNNING → SUCCEEDED | FAILED. Errors: 401; 403 (bearer, not owner, hold, imported-project protection); 404; 409 (live resources without consent, imported-project gates, idempotency body mismatch); 422 (unknown body field, non-UUID Idempotency-Key); 500. Idempotency/Concurrency: Idempotency-Key (UUID) is optional (recommended); the consent body is part of the fingerprint, so a replay with different consent is 409, never the recorded 202.