fix(docs): include navigation breadcrumbs in yml errors

[shubhamsinnh]

Summary

• append readable navigation breadcrumbs to docs config schema validation errors
• apply breadcrumbs to docs.yml, versions.yml, and products.yml validation paths
• add regression coverage for nested tab/section/page navigation errors

Fixes #10693

Testing

• D:\first-project\fern\node_modules\.bin\vitest.cmd --run src/__test__/formatNavigationConfigError.test.ts from packages/cli/yaml/docs-validator
• git diff --check

Notes

• I also tried npx -p node@22.13.0 -p pnpm@11.0.6 pnpm --filter @fern-api/docs-validator compile, but this sparse checkout fails on unresolved local workspace package type outputs, so it was not a clean validation signal.

[claude]

Claude Code Review

This pull request is from a fork — automated review is disabled. A repository maintainer can comment @claude review to run a one-time review.

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 3 additional findings.

[shubhamsinnh]

Hi! This PR is ready for review.

Most checks are passing now (compile, biome, lint, test, depcheck, boundaries, version validation, and seed result checks). The remaining test-ete failure appears to be due to Fern auth secrets not being available on this fork PR: the logs show Authentication required / missing FERN_TOKEN.

Please let me know if there is anything else I should update.

[devin-ai-integration]

Devin Review found 1 new potential issue.

View 4 additional findings in Devin Review.

[shubhamsinnh]

Hi @amckinney, just wanted to follow up on this when you get a chance.

This is for #10693, where docs config validation errors point to array indexes like $.navigation[5].layout[1], which makes the actual page/section hard to find in larger docs.yml files. I updated the formatter to include readable navigation breadcrumbs, and also addressed the root-level title case Devin flagged.

Would appreciate your review on whether this is the right place and shape for the fix. Happy to adjust if there’s a cleaner pattern you’d prefer.