added username (models.CharField) & searchable (models.BooleanField) to User model in lyric app; new ITs confirm functionality here; dashboard views now ensure that sharing a list w. an email address (as opposed to a username) neither confirms nor denies whether that email address has a registered account (ITs green)

src/apps/lyric/migrations/0002_user_searchable_user_username.py

@@ -0,0 +1,23 @@
+# Generated by Django 6.0 on 2026-03-02 01:32
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('lyric', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='user',
+            name='searchable',
+            field=models.BooleanField(default=False),
+        ),
+        migrations.AddField(
+            model_name='user',
+            name='username',
+            field=models.CharField(blank=True, max_length=35, null=True, unique=True),
+        ),
+    ]