feat: add getCheckRunByName to look up check run ID by commit ref and name

[HarshMN2345]

No description provided.

[greptile-apps]

Greptile Summary

This PR introduces getCheckRunByName, a new method that resolves a check-run ID from a commit ref and check name — allowing callers to look up an ID without storing it at creation time. The method is added as a throwing stub on the base Adapter and fully implemented on GitHub.

• GitHub::getCheckRunByName calls the GitHub check-runs API with the check_name filter, returns 0 on 404 (commit/repo not found), throws on other HTTP errors, and selects the highest ID among returned runs as a proxy for the most recently created one.
• Five integration tests cover the happy path, a name-mismatch returning 0, a missing repo returning 0, most-recent selection when multiple runs share a name, and a full create → look up → update workflow.

Confidence Score: 5/5

Safe to merge — the new method is a focused, well-tested addition with no changes to existing behavior.

The implementation correctly separates 404 (return 0) from other HTTP errors (throw), uses a straightforward API call with the check_name filter, and is covered by five integration tests exercising all meaningful code paths. No existing logic is modified.

No files require special attention.

Important Files Changed

Filename	Overview
src/VCS/Adapter.php	Adds the getCheckRunByName abstract stub with a clear doc comment; mirrors the pattern of all other adapter methods.
src/VCS/Adapter/Git/GitHub.php	Implements getCheckRunByName using the GitHub check-runs API with proper 404-returns-0 / other-errors-throw error handling and max(array_column(..., 'id')) to select the most recently created run.
tests/VCS/Adapter/GitHubTest.php	Five new integration tests covering: basic lookup, name mismatch returns 0, missing repo returns 0, most-recent selection, and end-to-end create-lookup-update workflow.

_{Reviews (5): Last reviewed commit: "fix: use filter=all + max(id) instead of..." | Re-trigger Greptile}