feat: Remove slug field from ResearchStudy model and update related references

research/models.py

@@ -1,13 +1,10 @@
 from django.db import models
 from django.conf import settings
 from django.urls import reverse
-from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
-from django.core.exceptions import ValidationError
 from generic.mixins import AuthorMixin
 from generic.models import CidUser
 from atlas.models import CaseCollection
-from loguru import logger
 
 
 class ResearchStudy(models.Model, AuthorMixin):
@@ -24,7 +21,6 @@ class ResearchStudy(models.Model, AuthorMixin):
         BULK_ONLY = "BULK", _("Bulk generation only")
 
     name = models.CharField(max_length=255)
-    slug = models.SlugField(max_length=100, unique=True)
     description = models.TextField(blank=True)
 
     active = models.BooleanField(default=True)
@@ -222,7 +218,7 @@ class ResearchParticipant(models.Model):
         verbose_name_plural = "Research Participants"
 
     def __str__(self):
-        return f"{self.study.slug}:{self.pseudo_id}"
+        return f"{self.study.pk}:{self.pseudo_id}"
 
     def is_prerequisite_satisfied(self):
         """Check if participant has completed prerequisite arm(s) for current assignment."""