character: significator field populated from seat on natus_save; my_tray_sig from Character when confirmed — TDD

Character.significator was already in the model but never set. natus_save now copies
seat.significator onto the Character on every save (draft + confirm). _role_select_context
overrides my_tray_sig from Character.significator when sky_confirmed, making Character
the authoritative source for the sig card displayed in the sea overlay.

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

src/apps/epic/views.py

@@ -352,14 +352,18 @@ def _role_select_context(room, user):
         elif user_role in _GRAVITY_ROLES:
             user_polarity = 'gravity'
         ctx["user_polarity"] = user_polarity
-        sky_confirmed = bool(
-            _canonical_seat and Character.objects.filter(
+        confirmed_char = (
+            Character.objects.filter(
                 seat=_canonical_seat,
                 confirmed_at__isnull=False,
                 retired_at__isnull=True,
-            ).exists()
+            ).first()
+            if _canonical_seat else None
         )
+        sky_confirmed = confirmed_char is not None
         ctx["sky_confirmed"] = sky_confirmed
+        if sky_confirmed:
+            ctx["my_tray_sig"] = confirmed_char.significator
 
     return ctx
 
@@ -1083,6 +1087,8 @@ def natus_save(request, room_id):
     char.house_system = body.get('house_system', Character.PORPHYRY)
     char.chart_data  = body.get('chart_data')
 
+    char.significator = seat.significator
+
     if body.get('action') == 'confirm':
         char.confirmed_at = timezone.now()