rename natus → sky across the codebase — natal chart abstraction is now sky throughout, since chart inputs aren't birthday-gated

Mechanical rename: 5 files (sky-wheel.js, _sky.scss, _sky_overlay.html, SkyWheelSpec.js x2), 24 in-place edits across templates/views/urls/SCSS/JS/tests/CLAUDE.md. URL names epic:natus_save → epic:sky_save (epic namespaced, no clash w. dashboard:sky_save), JS module NatusWheel → SkyWheel, DOM ids id_natus_* → id_sky_*, BEM classes natus-* → sky-*, dashboard sky_natus_data/sky_natus_preview collapsed to sky_data/sky_preview_data. No DB migration needed (User.sky_chart_data + GameEvent.SKY_SAVED already used sky-prefix). 778 ITs + Jasmine green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/apps/dashboard/views.py

@@ -287,7 +287,7 @@ def save_payment_method(request):
 
 # ── My Sky (personal natal chart) ────────────────────────────────────────────
 
-def _sky_natus_preview(request):
+def _sky_preview_data(request):
     """Shared preview logic — proxies to PySwiss, no DB writes."""
     date_str = request.GET.get('date')
     time_str = request.GET.get('time', '12:00')
@@ -380,7 +380,7 @@ def sky_view(request):
 
 @login_required(login_url="/")
 def sky_preview(request):
-    return _sky_natus_preview(request)
+    return _sky_preview_data(request)
 
 
 @login_required(login_url="/")
@@ -440,7 +440,7 @@ def sky_save(request):
 
 
 @login_required(login_url="/")
-def sky_natus_data(request):
+def sky_data(request):
     user = request.user
     if not user.sky_chart_data:
         return HttpResponse(status=404)