Add canonical field and update synonym handling in Condition model

- Introduced a new `canonical` ForeignKey field in the Condition model to manage alias relationships.
- Enhanced synonym retrieval methods to prefer canonical names and handle aliases more effectively.
- Updated condition detail templates to reflect canonical status and improved synonym display.
- Implemented migration scripts to establish canonical relationships based on existing synonym links.

atlas/migrations/0087_alter_condition_canonical.py

@@ -0,0 +1,19 @@
+# Generated by Django 5.2.7 on 2025-11-20 22:35
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('atlas', '0086_add_canonical'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='condition',
+            name='canonical',
+            field=models.ForeignKey(blank=True, help_text='If set, this Condition is an alias and points to the canonical Condition.', null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='aliases', to='atlas.condition'),
+        ),
+    ]