Add Gatsby lockfile example and verified case study

[Ayush7614]

Summary

Add a real-world Gatsby monorepo lockfile snapshot and a verified baseline scan case study to CVE Lite CLI.

Motivation

Gatsby is a widely used static-site and meta-framework with a large Yarn Classic monorepo and a deep dependency graph spanning build tooling, plugins, and documentation apps. A committed lockfile snapshot and documented case study would:

• Extend framework coverage beyond Astro (pnpm) with a Yarn Classic lockfile format at production scale
• Show how CVE Lite CLI handles a mature SSG monorepo with a broad transitive vulnerability surface
• Document verified baseline findings, fix command groups, and remaining risk without applying remediation
• Provide a side-by-side comparison with yarn npm audit on the same lockfile

Preliminary scan (CVE Lite CLI v1.18.0, lockfile-only, 2026-05-27)

Metric	Value
Upstream revision (candidate)	1f38c85963fd6bcfa9ccee2f925e5e02b00eafbb
Lockfile	yarn.lock (Yarn Classic)
Resolved packages	3,568
Vulnerable packages	128 (160 OSV advisory matches)
Severity	9 critical · 66 high · 42 medium · 11 low

Numbers are from a lockfile-only baseline scan and must be re-verified locally before publishing the case study.

Proposed changes

• Add examples/gatsby/ with package.json and yarn.lock pinned to a specific upstream commit
• Add website/docs/case-studies/gatsby.md with verified scan results (CVE Lite CLI version, yarn audit comparison, reproducible commands)
• Wire the case study into docs sidebar, README, examples/readme.md, and CHANGELOG

Scope

• Documentation and example fixture only
• No changes to scanner source code or existing examples
• All scan metrics must be reproduced locally before publishing (baseline only — no fake “after” remediation results)

Acceptance criteria

• Lockfile snapshot is pinned to a documented upstream revision
• Case study includes scan verification section with reproduce commands
• Comparison note explains CVE Lite vs native audit count differences (if totals differ)
• Baseline findings table matches live scan JSON output

[Ayush7614]

cc: @sonukapoor

[sonukapoor]

Thanks for the thorough preliminary scan - the numbers look solid. Good to go. Use the Astro or Turborepo case studies as the format reference - same section order, same verified baseline requirement, no estimated "after" rows. Looking forward to the PR.

[Ayush7614]

PR for closing issue #494