Provision or replace this node's recovery repository

Provisions the repository, or continues a provisioning attempt a crash left half done. Idempotent: the same key answers the operation it already created. With replace: true, registers a new repository volume generation and moves the active pointer to it; the previous repository and its points are kept. A request that builds or replaces the repository takes the node's repository lock, the lock every capture, verification, and restore holds, so it answers 409 and is not recorded while one of them (or another replacement) runs, or while a stale repository lock awaits a reviewed release. A repeated request on a working repository changes nothing and takes no lock. Requires permission to change system settings. Only a Full Admin API token may call it; any other scope is refused with 403 SCOPE_DENIED.