Refactor Condition model: remove legacy synonym and primary fields, introduce canonical field for aliasing. Update related documentation.

atlas/models.py

@@ -231,12 +231,6 @@ class Finding(SynMixin, models.Model):
 
 class Condition(SynMixin, models.Model):
     name = models.CharField(max_length=255, unique=True)
-
-    synonym = models.ManyToManyField(
-        "self",
-        blank=True,
-        help_text="Use if a direct synonym for the condition exists, e.g. 'Wegener granulomatosis' and 'Granulomatosis with Polyangitis'.",
-    )
     # New canonical/alias field (Option B): if set, this Condition is an alias
     # and points to the canonical/master Condition.
     canonical = models.ForeignKey(
@@ -256,10 +250,10 @@ class Condition(SynMixin, models.Model):
         help_text="Use if the condition could be considered a subset of another, e.g. 'Alzheimer disease' and 'Dementia'.",
     )
 
-    primary = models.BooleanField(
-        default="True",
-        help_text="Sets if this should be the canonical item, all other synonyms will then redirect to this by default.",
-    )
+    # Legacy fields `synonym` (M2M) and `primary` (boolean) have been removed.
+    # Canonical/aliases are represented by the `canonical` ForeignKey and
+    # the reverse `aliases` related_name. Use `get_synonyms()` /
+    # `canonical_condition` to access canonical groups.
 
     subspecialty = models.ManyToManyField(
         "subspecialty",