RDoc-4025, RDoc-4027 Fix vulnerable dependencies and flaky build

[poissoncorp]

Issue link

• https://issues.hibernatingrhinos.com/issue/RDoc-4025
• https://issues.hibernatingrhinos.com/issue/RDoc-4027

Additional description

Two independent changes:

RDoc-4025 - declare direct dependencies used by the build plugins.
The recent-guides / recent-samples plugins import js-yaml and image-size directly, but neither was declared in package.json (they resolved only through hoisting). Both are now declared so the build no longer relies on a transitive package staying hoisted. Dependency vulnerability remediation itself is tracked separately under RDoc-4026 (Enable Renovate).

RDoc-4027 - fix the flaky production build (Windows EMFILE).
The all-versions build issues a large, unbounded fan-out of concurrent fs.readFile calls and can exceed Windows' open-file limit, failing intermittently with EMFILE: too many open files. scripts/limit-docusaurus-file-reads.cjs caps the number of in-flight promise-based reads (Windows only; other platforms and callback-style reads are untouched) and replaces the previous scripts/patch-fs.cjs. Covered by a unit test.

Type of change

• Content - docs
• Content - cloud
• Content - guides
• Content - start pages/other
• New docs feature (consider updating /templates or readme)
• Bug fix
• Optimization
• Other

Changes in docs URLs

• No changes in docs URLs
• Articles are restructured, URLs will change, mapping is required (update /scripts/redirects.json file, set Documents Moved PR label)

Changes in UX/UI

• No changes in UX/UI
• Changes in UX/UI (include screenshots and description)