Update pnpm lockfile for React 19.0.0

The lockfile was generated with React 18.0.0 but package.json specifies
^19.0.0. This caused CI failures with --frozen-lockfile.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: justin808