Replaces the winit + raw-HWND-D3D11 shell with a native WinUI 3 UI via windows-reactor (a
declarative React-like framework backed by WinUI). The earlier "Reactor can't host a
swapchain" read was wrong — PR #4499 (merged 2026-06-01) added a SwapChainPanel widget with
`set_swap_chain` over `CreateSwapChainForComposition`. Builds + clippy + fmt green on
x86_64-pc-windows-msvc.
- Cargo: drop winit/raw-window-handle; add windows-reactor + the `windows` crate, both pinned
to the SAME windows-rs commit (b4129fcc) so the `IDXGISwapChain1` handed to `set_swap_chain`
satisfies reactor's `windows_core::Interface`. Reactor's build.rs downloads the Windows App
SDK NuGets + stages the bootstrap DLL/resources.pri — it requires `CARGO_WORKSPACE_DIR` set
(now in the VM build env); /temp + /winmd gitignored.
- present.rs: composition swapchain (B8G8R8A8 FLIP_SEQUENTIAL premultiplied) bound to the
SwapChainPanel; WARP fallback, runtime D3DCompile shaders, dynamic RGBA texture, Contain-fit
letterbox; driven by reactor's per-frame `on_rendering`.
- app.rs: the WinUI 3 shell — host list (live mDNS + saved + manual), settings (resolution/
refresh/mic combos+toggle), in-app SPAKE2 PIN pairing screen, and the stream page. Trust gate
mirrors the GTK client (pinned → silent, pair=optional → TOFU, else PIN); a pinned-fp
mismatch routes to re-pair. The session pump + decoded-frame handoff cross to the UI thread
via a Mutex side-channel + thread-locals (the SwapChainPanel sample's pattern).
- gamepad: `ctl` sender now `Arc<Mutex<…>>` so GamepadService is `Sync` (shared across the UI
and session-pump threads). main.rs: windowed = in-app UI; `--headless`/`--discover` keep the
CLI paths.
Not yet wired: raw stream keyboard/mouse input (next commit — reactor exposes no raw key/
pointer events, so it needs Win32 low-level hooks or Microsoft.UI.Xaml bindings). On-glass
validation pending a display (the dev VM is headless/GPU-less).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
enricobuehler
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