test(ci): Reproducible test harness for release notes pipeline

[sfreudenthaler]

Summary

A checked-in bash script that creates a complete end-to-end test harness in any GitHub repo (primarily dotCMS/core-workflow-test) for validating the AI release notes pipeline. Includes cleanup support.

Acceptance Criteria

• Creates 5 PRs with specific labels covering all signal types:
  • Feature (feature label)
  • Bug fix (bug label)
  • Rollback-unsafe (AI: Not Safe To Rollback label)
  • Skip (Changelog: Skip label)
  • Infrastructure (infrastructure label)
• Creates 2 standard releases (v26.03.17-01 after PRs 1-3, v26.03.17-02 after PRs 4-5)
• Creates filter test tags (v26.03.17_lts_v01, dotcms-cli-26.03.17-01)
• Ensures required labels exist (idempotent label creation)
• --cleanup flag tears down releases, tags, and branches
• --repo flag for targeting any repo (defaults to current)
• Prints expected behavior summary at the end

Technical Details

File: .github/scripts/gather-release-data/test/create-test-harness.sh

Usage:

# Create test harness
.github/scripts/gather-release-data/test/create-test-harness.sh --repo dotCMS/core-workflow-test

# Tear down
.github/scripts/gather-release-data/test/create-test-harness.sh --cleanup --repo dotCMS/core-workflow-test

Expected test results:

Test	Expected
v26.03.17-01 → v26.03.17-02	2 commits, 1 change (infra), 1 skipped, 0 rollback-unsafe
v26.02.10-99 → v26.03.17-01	3+ PRs (feature, bug, rollback-unsafe), 1 rollback-unsafe
Single-tag v26.03.17-02	Auto-detects v26.03.17-01 as previous
Backfill with v26.03.17_lts_v01	Workflow skips (LTS tag filter)
Backfill with dotcms-cli-26.03.17-01	Workflow skips (CLI tag filter)
Re-trigger with notes present	Skips (idempotency check)

Status: ✅ Implemented — test harness already created in dotCMS/core-workflow-test

References

• Parent Epic: epic(ci): Automated release notes for GitHub releases #35011
• Test PR: dotCMS/core-workflow-test#451