Adds `pnpm admin:grant-license` command to grant free licenses to
contributors without credit cards. Creates customer, generates license,
saves to DB, and sends welcome email via Resend.
Usage:
pnpm admin:grant-license --email contributor@example.com
pnpm admin:grant-license --email x@y.com --name "Name" --plan team
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>