RHDH PR / MR opener

Shared script for push + open. Caller owns the commit and /mutation-gate approval when an agent is driving. Weekly bots may call the script unattended.

Boundaries

• Not /rhdh-pr-create (plugin changesets, recordings, monorepo publish).
• Does call /rhdh-jira-link link-pr-mr.js when --issue or JIRA_ISSUE is set.
• Skips Jira when no key is known — never invent one.
• Midstream createPR.sh (distgit) stays for updateBaseImages.sh until a later migration.

Script