Delete Project

Delete a project in one of two modes. **Detach** (the default, no body or `mode: detach`): only the grouping row is removed; every resource in the project moves to the implicit Default project. Refused with 409 `project_has_scoped_credentials` while an API key, service account, vault credential, webhook endpoint, member grant or pending invite is scoped to the project, because detaching any of those would silently widen it. **Purge** (`mode: purge` with `confirm` equal to the project's name): available only on an ARCHIVED project, because an irreversible teardown needs a state you can sit in and reverse first; a live project is refused with the coded `409 project_not_archived`. Archive the project, confirm it is the one you mean, then purge. The project is removed WITH its contents in one transaction. Agents (with their tests), knowledge bases (with their documents), tools, audio assets, scoped webhook endpoints and scoped vault credentials are deleted; API keys and service accounts pinned to the project are revoked; member grants and pending-invite scopes on the project are cleared. Conversations, callers, batch calls, suite runs and memories are operational records and survive exactly as on a detach: a conversation keeps its frozen attribution, the others move to the Default project. Refused with 409 while a phone number is attached (release or move it first), while a member's only project grant is this one, or while a live invite carries only this project (clearing either would widen that person to the whole workspace, the invite one acceptance earlier). Preview either mode with `GET /v1/projects/{project_id}/teardown`. The 409 carries the blockers under `error.details.blockers` (`kind`, typed `id`, `name`, and the `blocks` modes each refuses), their total under `error.details.blocker_count`, and, for existing clients, the same rows under `error.details.credentials`. The lists are capped at 50 rows; the counts are not, and the refusal is decided on the count.