Grid.__init__() now auto-creates a GridView that shares the Grid's
data via aliasing shared_ptr. This enables the Grid/GridView split:
- PyUIGridObject gains a `view` member (shared_ptr<UIGridView>)
- Grid.view property exposes the auto-created GridView (read-only)
- Rendering property setters (center_x/y, zoom, camera_rotation, x, y,
w, h) sync changes to the view automatically
- Grid still works as UIDrawable in scenes (no substitution) — backward
compatible with all existing code and subclasses
- GridView.grid returns the original Grid with identity preservation
- Explicit GridViews (created by user) are independent of Grid's own
rendering properties
Addresses #252. All 260 tests pass, no breaking changes.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
