Admin Users tab: search, filter free/paid, view/edit details, delete

**Sprint 7 - Admin Tools & Handoff**

Complete the Admin Users tab functionality:
- Admin can see a list of users
- Search users by name and email
- Filter out free/paid subscribers
- Click on user name to view user settings page
- Admin can give a subscription to users who are not subscribed
- Admin can delete users
- Estimated: 5 hours