Retrieve the full details of a ticket by its `ticket_id`. The response includes the ticket's title, description, current phase, whether it's archived, the complete comment thread, and any supersede/prerequisite relationships. Comments contain analyst findings, reviewer notes, QA results, and messages from the user or manager. Use this tool when you need to review a ticket's full history, check what reviewers or analysts have already found, or understand the current state of a ticket before taking action on it. The `ticket_id` may be a bare number (e.g. `123`) or the fully prefixed form (e.g. `workspace-123`); only tickets from the current workspace are accessible.