MY SKY: full-page layout polish — aperture pinning, wheel-above-form, centred wheel

- sky_view passes page_class="page-sky" so the footer pins correctly
- _natus.scss: page-sky aperture block (mirrors page-wallet pattern);
  sky-page stacks wheel above form via flex order + page-level scroll;
  wheel col uses aspect-ratio:1/1 so it takes natural square size without
  compressing to fit the form
- natus-wheel.js: _layout() sets viewBox + preserveAspectRatio="xMidYMid meet"
  so the wheel is always centred inside the SVG element regardless of its
  aspect ratio (fixes left-alignment in the dashboard applet)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/apps/dashboard/views.py

@@ -317,6 +317,7 @@ def sky_view(request):
         "saved_sky":   request.user.sky_chart_data,
         "saved_birth_dt":    request.user.sky_birth_dt,
         "saved_birth_place": request.user.sky_birth_place,
+        "page_class":  "page-sky",
     })