chore(qa): add PROJ-16 testdata cleanup script

[Wachhund]

Purpose

• Documentation update
• Bug fix
• New feature
• Refactor/maintenance
• Security hardening
• Other (QA utility script)

Related Features / Issues

• PROJ: PROJ-16
• Issue: n/a

Overview of Changes

• Adds a dedicated QA helper script: script/qa/cleanup-proj16-testdata.php.
• Script is intended for test-data cleanup after PROJ-16 validation runs.
• No runtime/controller/model behavior changed.
• No schema or migration changes.

QA / Verification

• composer run ci:lint: not run (utility script only)
• composer run test: not run
• composer run analyse: not run
• composer run cs-check: not run
• Manual checks:
  • Verified script exists and is committed in expected location.
  • Verified no unrelated file changes in this PR.

Deployment Impact

• No deploy impact
• Requires deploy runbook update
• Requires environment/config changes
• Requires migration
• Rollback notes: revert this PR if the utility is not needed.

Reviewer Focus

• Confirm naming/location (script/qa) is aligned with repo conventions.
• Confirm scope is intentionally limited to QA cleanup support.

Checklist

• Scope matches linked PROJ / issue
• No secrets or credentials committed
• Docs updated where needed
• Backward compatibility considered
• Ready to merge

[Copilot]

Pull request overview

This PR adds a QA utility script to clean up test data created during PROJ-16 validation runs. The script is designed to remove specific test users and their associated data from shared environments.

Changes:

• Adds script/qa/cleanup-proj16-testdata.php for removing PROJ-16 test users and related data
• Provides dry-run mode for previewing deletions before execution
• Targets specific test user accounts (qa_proj16_sender, qa_proj16_recipient)

[Copilot]

@Wachhund I've opened a new pull request, #13, to work on those changes. Once the pull request is ready, I'll request review from you.