Convert package manager from npm to pnpm

[phrazzld]

Summary

Convert the project from npm to pnpm for improved performance, disk space efficiency, and dependency safety.

Benefits

• Performance: 2-3x faster installs through content-addressable storage
• Disk Space: Significant savings via shared dependency store across projects
• Dependency Safety: Stricter resolution prevents phantom dependencies
• Better Monorepo Support: Future-proofing for potential monorepo structure

Tasks

Core Package Management

• Remove package-lock.json
• Generate pnpm-lock.yaml via pnpm install
• Update .gitignore for pnpm-specific files
• Add pnpm installation instructions to README

Git Hooks Updates

• Update .husky/pre-push (npm commands: lint, typecheck, build, build-storybook, test:coverage)
• Update .husky/pre-commit (likely contains npm commands)
• Update .husky/post-commit (may reference npm)
• Update .husky/pre-push-security (npm audit commands)

Scripts & Tooling

• Update scripts/audit-filter*.ts (contains npm audit references)
• Update scripts/validate-structured-logging.sh (may contain npm commands)
• Verify all build/deployment scripts work with pnpm
• Test security audit filtering with pnpm audit

Testing & Validation

• Full test suite passes with pnpm
• All builds work (main app, Storybook)
• Pre-commit/pre-push hooks work correctly
• Security scanning still functions properly
• Edge Runtime compatibility maintained

Documentation

• Update CLAUDE.md with pnpm commands
• Update any development setup documentation
• Add team migration instructions

Acceptance Criteria

• All npm references replaced with pnpm equivalents
• Full CI/CD pipeline works with pnpm
• Git hooks and security scripts function properly
• Team can successfully develop using pnpm
• Performance improvement is measurable

Notes

• Estimated effort: 4-6 hours for careful, tested conversion
• Should be done on a separate branch first for validation
• Team will need to install pnpm (via npm install -g pnpm or corepack)
• Drop-in replacement - same registry, similar commands

Related

• Consider enabling corepack for automatic pnpm version management
• May want to add .npmrc with pnpm-specific optimizations