create-pr

Create a Pull Request for a Marshroom cart issue matching the current branch.

Critical Requirements

• state.json update is MANDATORY. After creating the PR, you MUST update the issue status to pending with prNumber and prURL in ${MARSHROOM_STATE:-~/.config/marshroom/state.json}. If this fails, stop and report the error — do NOT silently continue.
• Use marsh pr if available; otherwise fall back to direct jq atomic write (see step 9).

Steps