Validate the current Pull Request against Marshroom conventions. Steps: 1. Read and parse the JSON 2. Run to get the current branch name 3. Find the cart entry whose matches the current git branch. If no match, tell the user they're not on a cart issue branch 4. Get the current PR info: 5. Validate the following: Branch Name Check: - The PR's head branch should match the matched cart entry's - Expected format: or - If mismatched, show: "Branch mismatch: expected '{branchName}', got '{actual}'" PR Body Check: - The body MUST contain - If missing, suggest: Status Check: - Read the field from th…