Configure CI status integration

Integrate the CI system so its run statuses appear on pull requests for the core-library repo. Connect the pipeline named nightly-ci and ensure it reports pending, success, and failure back to pull requests; set the integration secret and test it by triggering a run on branch feature/fast-serialization. Confirm the PR shows the status within five minutes.

Before I wire CI status into pull requests, make the integration less noisy: put the most actionable status first, collapse long logs behind a link, and annotate failures with the likely failing stage. Flag where timeouts or environment differences will produce false negatives and recommend how to map CI stages to readable labels for reviewers.

I updated the integration token for nightly-ci and jobs now run on the CI side, but pull requests still show no status checks. The release engineer is pressing for visibility and I can't tell if the problem is token scope, webhook delivery failures, or mismatched check names. What's the highest-probability diagnosis and the fastest corrective actions I should try to get statuses reporting again?

Some repos show clear CI statuses and valuable failure messages; others bury results or spam reviewers with duplicate checks. Reviewers start ignoring the whole section. I want a cross-repo standard so CI feedback is concise and trusted. Recommend a three-part policy: naming conventions for checks, which checks must show inline, and a process to reduce duplicate or noisy statuses.