Driver

CLAUDE.md and .claude/rules/workflow-gates.md mandate one ticket per PR. The PR title validator already enforces a single ticket reference. The PR body is not checked — a title with one ticket can coexist with Closes #1 Closes #2 Closes #3 in the body, and the latter is what GitHub acts on at merge time (auto-close). This loophole defeats the rule's purpose.

Scope

Add a PR-body check to validate-pr-create.sh:

1. Scan the body for the GitHub closing-keyword patterns, case-insensitive, with #NNN: close #N, closes #N, closed #N, fix #N, fixes #N, fixed #N, resolve #N, resolves #N, resolved #N.

2. Count distinct issue numbers referenced.

3. If count > 1: exit 2 with a message listing the referenced issues and explaining the rule.

4. Configurable override for teams that explicitly want multi-ticket PRs:

   # .claude/project-config.json
   pr:
     allow_multiple_closes: false   # default

5. Skip marker: <!-- multi-close: approved --> for the rare legitimate umbrella PR (e.g. a rollback PR closing a set of tickets together).

Acceptance Criteria

• A PR body with Closes #1 Closes #2 is blocked.
• A PR body with Closes #1 (exactly one) passes.
• A PR body referencing #2 without a closing keyword does NOT count (it's a cross-reference, not an auto-close).
• allow_multiple_closes: true disables the check for teams that opt in.
• Skip marker passes with a warning.
• Fixtures in .claude/hooks/tests/ cover: one close, two closes, cross-ref without keyword, skip marker, opt-in config.

Risks / Dependencies

• Some teams legitimately batch rollbacks or revert multiple tickets in one PR. Mitigation: opt-in config + skip marker.
• Keyword regex needs to be conservative — don't match Closes #1-related code or fixes inside code blocks. Mitigation: strip code blocks before scanning; require whitespace or line-start before the keyword.

Glossary