Move to a different branch in the Graphite stack. User input: $ARGUMENTS.

Dispatch by argument

• up or empty + "next up" intent → gt up (alias gt u); accept a trailing number for steps (gt up 2).
• down → gt down (gt d); same step semantics.
• top → gt top (gt t).
• bottom → gt bottom (gt b).
• trunk or main → gt checkout --trunk (gt co -t).
• A branch name → gt checkout <name> (gt co <name>).
• Empty / no argument → gt checkout (interactive picker — only run if the session supports interactive prompts; otherwise show gt ls and ask the user to pick).

Steps

1. If the working tree is dirty, run git status --short and confirm with the user — checkout will fail or carry the changes.
2. Run gt ls to show context.
3. Run the dispatched command.
4. Confirm with gt ls (the new current branch is marked ◉).

Notes

• When gt up or gt top hits a branch with multiple children, it prompts to disambiguate. In non-interactive contexts, pass the specific branch name instead.
• gt checkout -s <branch> switches to a branch and pulls its whole stack — useful when navigating to a teammate's stack after gt get.