- Adds two new GraphQL mutations, update_users_board_role and update_teams_board_role, to bulk set board roles for up to 200 users or 50 teams in a single call.
- Requires boards:write scope; role_name can be editor, contributor, or viewer (member only for agent users), and returns per‑ID success and failure lists.
- Users/teams must already be subscribed to the board; use add_users_to_board or add_teams_to_board to subscribe first.