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/tests/integrated/test_views.py

@@ -619,13 +619,13 @@ class SkySaveViewTest(TestCase):
         self.assertAlmostEqual(self.user.sky_chart_data["houses"]["asc"], 123.4)
 
 
-class SkyNatusDataViewTest(TestCase):
+class SkyDataViewTest(TestCase):
     def setUp(self):
         self.user = User.objects.create(email="disco@test.io")
         self.client.force_login(self.user)
 
     def test_returns_stored_chart_with_asc_preserved(self):
-        """sky_natus_data returns sky_chart_data — asc must match what was saved."""
+        """sky_data returns sky_chart_data — asc must match what was saved."""
         stored = {
             "planets": {},
             "houses": {"cusps": [float(i * 30) for i in range(12)], "asc": 236.1, "mc": 159.1},