note title equip: DON/DOFF buttons outside top-left corner; User.active_title FK; don/doff views; greeting updated via JS — TDD

- lyric/models.py: active_title = ForeignKey('drama.Note', null=True, SET_NULL)
- lyric migration 0020_add_active_title
- billboard/views.py: don_title + doff_title views; is_equipped per note_item context
- billboard/urls.py: note/<slug>/don + note/<slug>/doff routes
- _navbar.html: id_greeting_name span; shows active_title.slug|capfirst when set
- my_notes.html: .note-don-doff buttons (DON/DOFF, × when disabled); data-don-url/doff-url/title attrs
- note-page.js: _bindDonDoff() — DON POST sets greeting + swaps btn state; DOFF restores Earthman
- _note.scss: .note-don-doff position:absolute left:-1rem top:0; flex-direction:column gap:1.25rem
- ITs: NoteEquipTitleViewTest (5 tests); UserModelTest.test_active_title_* (3 tests)
- FT: NoteEquipTitleTest.test_don_equips_title_greeting_and_doff_restores

Code architected by Disco DeDisco <discodedisco@outlook.com>
Git commit message Co-Authored-By:
Claude Sonnet 4.6 <noreply@anthropic.com>

src/apps/lyric/tests/integrated/test_models.py

@@ -3,6 +3,7 @@ from django.contrib import auth
 from django.test import TestCase
 from django.utils import timezone
 
+from apps.drama.models import Note
 from apps.lyric.models import LoginToken, PaymentMethod, Token, User, Wallet
 
 
@@ -29,6 +30,27 @@ class UserModelTest(TestCase):
         user = User.objects.create(email="a@b.cde")
         self.assertFalse(user.searchable)
 
+    def test_active_title_is_null_by_default(self):
+        user = User.objects.create(email="a@b.cde")
+        self.assertIsNone(user.active_title)
+
+    def test_active_title_can_be_set_to_a_note(self):
+        user = User.objects.create(email="a@b.cde")
+        note = Note.objects.create(user=user, slug="stargazer", earned_at=timezone.now())
+        user.active_title = note
+        user.save(update_fields=["active_title"])
+        user.refresh_from_db()
+        self.assertEqual(user.active_title, note)
+
+    def test_clearing_note_nullifies_active_title(self):
+        user = User.objects.create(email="a@b.cde")
+        note = Note.objects.create(user=user, slug="stargazer", earned_at=timezone.now())
+        user.active_title = note
+        user.save(update_fields=["active_title"])
+        note.delete()
+        user.refresh_from_db()
+        self.assertIsNone(user.active_title)
+
 class LoginTokenModelTest(TestCase):
     def test_links_user_with_autogen_uid(self):
         login_token1 = LoginToken.objects.create(email="a@b.cde")