Guards

After a PR is opened from a git worktree, tells Claude if the worktree can be closed (clean and pushed) or what is still not saved.

Blocks commits without [TICKET] when the branch has a ticket, and commits that only fix linting or formatting; suggests the correct message.

Saves GitHub Actions minutes: blocks gh run watch/rerun and gh pr checks --watch, and warns when a second PR is opened in the session.