Resolve the official GitHub Actions identity for apply and validation, verify every required check binding, and preserve the caller plan. Add regression coverage for missing or incorrect bindings and invalid check producers. Refs: KofTwentyTwo/AppKit#27, KofTwentyTwo/AppKit#10 Co-Authored-By: Codex (GPT-6) <noreply@openai.com> Signed-off-by: James Maes <james@kof22.com>