Execute Ticket

Owns: one-ticket quality loop from semantic baseline through implementation, focused simplification, review isolation gates, QA coordination, and verification handoff.

It does not choose from a folder, parse legacy Markdown, update the run ledger, move ticket files, commit, push, open or edit PRs, merge, or clean worktrees.

Consume the normalized Ticket Envelope supplied by the caller. Verification semantics and the output record are owned by verification-audit.