break(metrics): 💥 Harden metrics public API

[haskou]

Summary

• add global instrumentation defaults to configureMetrics
• restrict the root package exports to the public entrypoints
• expose advanced APIs through contracts and model subpaths
• include structured error details in failure logs
• document Prometheus cardinality rules

Impact

This is a breaking API hardening change because support/model exports are no longer re-exported from the package root.

Validation

• yarn lint
• yarn typecheck
• yarn test:coverage
• yarn docs:build
• yarn test:package
• yarn build

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 46f798f34b

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!