Purge Chat Session

Permanently destroy a conversation's stored content. IRREVERSIBLE.

Messages are deleted, trace content is scrubbed, and the title is cleared; a stub row survives as the record of the purge. Transient conversational state on the chat backend expires within approximately 24 hours.

Deliberately NOT available to retrieval tokens: they carry a single query-only scope minted for embedded widgets, and granting them irreversible deletion would be a least-privilege regression.