First Phase 1D migration cluster. `uikit_refresh_safe_insets` reads
`safeAreaInsets` through `#objc_call(UIEdgeInsets)` instead of the
hand-typed `objc_msgSend` cast + `sel_registerName` triple, and a dead
`sel_safe_insets` selector decl in `uikit_scene_will_connect_ios` goes
away with it. Net -3 lines.
iOS-sim chess regression smoke: SxChess launches, board renders with
correct status-bar clearance — `safe_top` is populated correctly,
which is the actual ABI under test (32 B HFA returned in v0..v3).
bcbf2ace22