Backend — API Endpoints for Entity Management (CRUD)

[specfor]

Create the REST API endpoints necessary for a System Admin to manage Entities.

• POST /api/v1/entities - Create a new entity.
• GET /api/v1/entities - List all entities.
• PUT /api/v1/entities/:id - Update entity details.
• DELETE /api/v1/entities/:id - Remove an entity.
• Ensure route-level middleware restricts access to System Admins only.