Bug/display the registered doctors instead of all doctors in queues

Summary

This Merge Request updates the queue management interfaces (Coordinator and Volunteer views) to display only doctors registered for the current medical camp. Previously, the system displayed all doctors across all camps, which created confusion and risked incorrect patient assignments.

The update ensures that only active, camp-registered doctors are visible in queue filtering and selection interfaces.

Problem Statement

The queue management pages previously fetched and displayed all doctors stored in the system, regardless of their association with the current medical camp.

This caused:

• Visibility of doctors from past camps
• Confusion for coordinators and volunteers
• Risk of assigning patients to inactive or unavailable doctors
• Inconsistent filtering behavior in queue views

Behavior Changes Before

• Displayed all doctors from all camps
• Allowed filtering by doctors not registered for current camp
• Risk of incorrect doctor assignment
• Reduced clarity during active camps

After

• Displays only doctors registered for the current/latest camp
• Filter buttons show only active camp doctors
• "All" / "All Doctors" filter still functions correctly
• Prevents assignment to inactive doctors
• Improves clarity and operational efficiency during camps

Impact

• Improves coordinator and volunteer user experience
• Reduces risk of patient flow errors
• Aligns frontend behavior with real-world medical camp workflow
• Ensures proper usage of existing backend API