Introduce Hard Limits on User Request Submissions

To enhance system management and maintain service quality, we need to implement a feature that allows setting hard limits on the number of concurrent requests a user can have, and the number of requests they can submit within a certain period. This feature should be adjustable by administrators, allowing them to define and modify these limits as needed to suit varying operational requirements and user capacities. The implementation of this feature will prevent system overload, ensure fair resource allocation, and help in maintaining a consistent quality of service across all user interactions.

Add an easy way to visualize remaining / concurrent requests from the client's dashboard.