Dispatch Codex bridge workflow with actions permission

[Pigbibi]

Summary

• trigger CryptoCodexAuditBridge via workflow_dispatch instead of repository_dispatch
• request actions:write for the cross-repo App token instead of contents:write
• update workflow config tests for the new dispatch route

Verification

• python -m pytest tests/test_monthly_publish_workflow_config.py -q
• PyYAML parsed .github/workflows/monthly_publish.yml
• git diff --check