Implement Administrative User Management #74

To manage the user base, administrators need a dedicated and secure interface.

• Secure Admin Endpoints: Create a new set of FastAPI endpoints under a prefix like /api/admin/. These endpoints will handle CRUD (Create, Read, Update, Delete) operations for users. Access must be restricted by a dependency that verifies the requesting user has an admin role.
• Build Admin Dashboard: Develop a new section in the Vue frontend, accessible only to administrators. This dashboard should provide a user-friendly interface for viewing all users and performing administrative actions like disabling accounts or changing user roles.