Draft: Resolve "feat(api): Implement Specialization-Based Assignment & Multi-Queue Management"

Description

This merge request implements the full Specialization-Based Assignment workflow, replacing the legacy doctor-centric assignment model. It allows volunteers to assign patients to medical specializations (e.g., ENT, General Physician) and enables doctors to claim patients from these specialization pools.

Key Features & Changes:

1. Database Strategy (Phase 1):
   • Updated ConsultationQueue table to support specialization and nullable doctor_id.
   • Added automated data migration to backfill specialization for existing records.
2. Volunteer Workflow (Phase 2):
   • Added POST /api/v1/queue/assign: Assign patient to one or more specializations.
   • Added GET /api/v1/queue/patient/{book_no}/all: View all active queues for a patient.
3. Doctor Workflow (Phase 3):
   • Added GET /api/v1/queue/specialization/{name}: Fetch the "Pool" of waiting patients + claimed patients.
   • Updated "Start Consultation" logic to assign the doctor_id (Claiming).
   • Implemented "Multi-Queue State Management": Putting parallel queues on hold when consultation starts.

Checklist

• Code follows project API guidelines.
• Tests for API endpoints are included and passing.
• API documentation is updated (if applicable).
• Performance considerations have been addressed.

Related Issue(s)