Strips invite-by-email mode from admin user management UI and API. POST /api/admin/users now always requires password parameter for direct user creation. Removes mode toggle, conditional password field, and invite logic branches. Simplifies user creation flow to single path. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01RkCfBY9L5y3SZ6uaKZzLCV