CHW-5710 SCIMTokenStoreFailed

failed to manage SCIM token; retry shortly or check /healthz

Default message: failed to manage SCIM token; retry shortly or check /healthz
HTTP status: 500 (server)

Problem. /api/orgs/{org_id}/scim/tokens* returned 500. Cause. A backing DB call failed — listing tokens, deleting a token, inserting a new token, generating random bytes for the plaintext, or loading the server-side pepper used to HMAC token hashes. Fix. Retry shortly; pepper-availability failures specifically indicate a DB issue, since the pepper is persisted in the settings table. HTTP 500.