v0.25.1

wgpu desktop backend (experimental) — new feature = "wgpu" runs mirui on Vulkan / Metal / DX12 / OpenGL ES through a winit window, with one render pass per frame, a uniform ring buffer for batched draws, and shared bind groups whose binding 1 carries a dynamic offset.

Added

• feature = "wgpu" — opt-in cross-platform GPU backend on wgpu 29 and winit 0.30.
  • mirui::surface::wgpu_surface::WgpuSurface + mirui::draw::wgpu_render::WgpuRendererFactory.
  • 4× MSAA, perspective-correct quad blit (Transform3D::from_quad recovers the homography), rounded-rect SDF for both axis-aligned and 2.5D quad widgets, glyph atlas, lyon-tessellated paths.
  • Mailbox > Immediate > Fifo present-mode preference; Fifo is the universal fallback.
  • Per-draw set_scissor_rect derived from each command's logical clip, clamped to the swapchain extent.
• gallery::run picks the backend at compile time: --features wgpu > --features sdl-gpu > --features sdl (default).
• gallery/examples/wgpu_smoke.rs — minimal hello window for the wgpu path.

Changed

• mirui::cache::Cache backs the wgpu render-pipeline cache. Count(N) is the right knob for "admit everything, never evict"; MaxSize::Disabled means "no insertion at all" and is no longer used for that purpose.
• gallery::run requires a Send + 'static builder closure so wgpu shares one demo entrypoint with sdl / sdl-gpu.

Fixed

• Canvas::clear(area, color) honours area. The wgpu impl was overwriting the whole display, defeating dirty-region renderers that called clear with a sub-rect.

Limitations on the wgpu backend

• macOS trackpad two-finger scroll feels less responsive than on the sdl backend.
• Pinch and rotation gestures are not delivered as input events.
• ColorFormat::RGB565 / RGB565Swapped textures are skipped by Canvas::blit; convert to RGB888 / RGBA8888 first.