Function window_metrics 

pub fn window_metrics(
    physical: (u32, u32),
    scale: f64,
    insets: WindowInsets,
) -> WindowMetrics

Assemble the app-facing WindowMetrics from a shell’s raw surface dimensions, its already-sanitize_scaled scale, and the window’s already-logical WindowInsets.

The one place the three shells agree on units. physical is the surface’s device-pixel size (Android’s nativeOnSurfaceChanged pair, iOS’s frust_resize pair, winit’s inner_size()), converted to logical px here through logical_size — so WindowMetrics::size is logical on every platform, exactly like the coordinates and insets that already cross this boundary (docs/CODE_STANDARDS.md’s physical-at-FFI/logical-inside rule). insets is passed through unchanged because each shell has already resolved it to logical px via logical_insets (Android divides by its display density, iOS uses the identity scale because UIKit hands over points) — this must never re-divide it.

WindowMetrics::orientation is derived from the logical size by WindowMetrics::new; no platform callback carries an orientation enum.

scale must already have passed through sanitize_scale (finite, strictly positive) — the same trust contract logical_size and logical_insets state, so a shell sanitizes the platform density once per use and feeds the identical value to all three.