Capture actual Mutter and DXGI cursor metadata, preserve Retina artwork, and invalidate cursor identities when physical pixels or DPI change. Keep straight-alpha colors during native cursor resizing and correct the Windows XOR outline offset.
Verified all six Mac/Linux/Windows directions with real pointer movement, arrow/I-beam/crosshair transitions, adaptive zoom off/on/off, Original view, and live DPI changes. Requested debug builds and focused native/Flutter regressions pass.
Keep Linux/macOS bitmap sizing and painted cursor DPI
conversion consistent, and derive hotspots from the actual scaled bitmap.
Pad tall Linux native cursor buffers with transparency to
preserve the lower half in the hardware cursor plane.
Cover bitmap sizing, hotspots, artwork preservation,
and painting with focused regression tests.
