[Chore] Update dependencies to latest ncu versions and clear npm audit findings

Summary

Update npm dependencies to the latest versions reported by ncu at implementation time, and reduce npm audit vulnerabilities as far as is rational without risky breakage.

Details

Direct dependency is currently vitepress@^1.6.4. Run ncu during implementation and bump packages to the latest stable versions it reports.

Also address known transitive vulnerabilities (today: vite via vitepress, already partially mitigated with an esbuild override). Prefer npm overrides for patched transitive versions when a direct bump is not available, and follow .ai-tasks/update-deps-security-notes.md for the security review.

Scope:

• Update package.json / package-lock.json via ncu + npm install
• Clear or reduce medium/high/critical npm audit findings where a safe override or upgrade exists
• Do not chase low-severity noise or force major upgrades that break the docs site
• Keep VitePress build working (npm run docs:build)

Out of scope:

• Content/documentation page edits
• Large refactors unrelated to dependency resolution

Checklist

• Run ncu and update dependencies to the latest versions available at implementation time
• Refresh the lockfile with npm install
• Apply rational fixes for medium/high/critical npm audit findings (overrides only when needed)
• Follow .ai-tasks/update-deps-security-notes.md (dependency diff, audit, suspicious packages/scripts, lockfile integrity, build smoke check)
• Confirm npm run docs:build succeeds
• Summarize remaining vulnerabilities that cannot be fixed without breaking changes

Notes

PR will be linked here after creation.

Suggested PR title: Chore: Update dependencies and clear npm audit findings

Security review checklist reference: .ai-tasks/update-deps-security-notes.md

Verification

• ncu reports no remaining outdated direct dependencies (or remaining gaps are documented)
• npm audit has no unresolved medium/high/critical issues that can be fixed rationally
• npm run docs:build completes without errors
• Security notes checklist items are covered in the PR description

Start with package.json, package-lock.json, and .ai-tasks/update-deps-security-notes.md. Run ncu, npm install, and npm audit to identify updates and rational security fixes, then verify npm run docs:build. Done means safe medium/high/critical findings are addressed or documented, the lockfile and security notes are refreshed, and the build succeeds.