pub const PREVIEW_CANVAS_WIDTH: u32 = 720;Expand description
Frame width the camera preview canvas paints at — must match the
capture size (screen_app::preview::pipeline::PREVIEW_WIDTH, 720
since M-QUAL.3) so the polled BGRA bytes fit the canvas
pixel-for-pixel (putImageData does not scale). The two crates
can’t share a constant (native vs wasm), so keep them in lockstep.