chore: upgrade pnpm from v9 to v10

[Viktor Yang (viktor-yang)]

Summary

• Upgrade pnpm from 9.15.9 to 10.34.1 across all packageManager and engines fields
• Update .npmrc hoist patterns to use wildcards (*eslint*, *stylelint*, *prettier*) for pnpm v10 compatibility
• Add onlyBuiltDependencies and ignoredBuiltDependencies config to package.json (pnpm v10 requires explicit allowlist for postinstall scripts)
• Update lockfile to pnpm v10 format: removes old braces@2.3.2 and related legacy packages, enforces braces@3.0.3 override
• Update CONTRIBUTING.md setup instructions to reference pnpm v10

Test plan

• pnpm install completes without errors
• pnpm run build passes
• pnpm run lint passes
• pnpm test passes
• CI passes on this branch