feat(windows-client): winit + D3D11 present, WASAPI render, input — builds live on MSVC

Builds on the prior headless scaffold (which was committed but never VM-built — its
audio.rs had two non-compiling wasapi calls). This makes the whole crate build + clippy
+ fmt + test green on x86_64-pc-windows-msvc and adds the windowed client.

- Fix audio.rs: `DeviceEnumerator::new()?.get_default_device(...)` (the free fn doesn't
  exist) and the 3-arg `write_to_device` (wasapi 0.23). WASAPI shared-mode event-driven
  render + mic capture now compile and link.
- present.rs: D3D11 renderer with WARP fallback (GPU-less dev box), runtime-compiled
  fullscreen-triangle shaders, dynamic RGBA video-texture upload, Contain-fit letterbox
  draw, and a flip-model swapchain on the window HWND.
- app.rs: winit 0.30 ApplicationHandler — present loop + Moonlight-style click-to-capture
  input (keyboard via the physical-KeyCode→VK keymap, absolute mouse, wheel, F11), held
  state flushed on release/focus-loss.
- keymap.rs: winit physical KeyCode → Windows VK (layout-independent positional mapping,
  the analogue of the Linux client's evdev table).
- main.rs: windowed default + `--headless` counting mode, `--discover` (mDNS list),
  `--pair PIN` (SPAKE2 ceremony), `--pin HEX`/known-host/TOFU trust, settings-backed
  CLI defaults.

UI decision: winit + raw D3D11 (the bootstrap doc's sanctioned fallback), confirmed by a
research pass — windows-rs "Reactor" ships no SwapChainPanel / SetSwapChain escape hatch,
so it can't host the presenter; winit+WARP validates on the GPU-less VM. Native-chrome
host-list/settings GUI + D3D11VA hardware decode + 10-bit/HDR present are follow-ups.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/punktfunk-client-windows/Cargo.toml

@@ -21,6 +21,28 @@ path = "src/main.rs"
 # is Sync (mutexed plane receivers), so it drops into a UI app cleanly.
 punktfunk-core = { path = "../punktfunk-core", features = ["quic"] }
 
+# Win32 / Direct3D11 / DXGI surface for the present path + raw input. Software (WARP) device on
+# the GPU-less dev box; the same code drives a hardware adapter on a real GPU.
+windows = { version = "0.62", features = [
+    "Win32_Foundation",
+    "Win32_System_Com",
+    "Win32_Graphics_Dxgi",
+    "Win32_Graphics_Dxgi_Common",
+    "Win32_Graphics_Direct3D",
+    "Win32_Graphics_Direct3D11",
+    "Win32_Graphics_Direct3D_Fxc",
+    "Win32_UI_Input",
+    "Win32_UI_Input_KeyboardAndMouse",
+    "Win32_UI_WindowsAndMessaging",
+    "Win32_UI_HiDpi",
+] }
+
+# UI shell: a winit window + a raw DXGI flip-model swapchain on its HWND (the proven present
+# path; the WinUI3/Reactor option is a documented follow-up). raw-window-handle extracts the
+# HWND for swapchain creation.
+winit = "0.30"
+raw-window-handle = "0.6"
+
 # Video decode (same FFmpeg pin as the host/Linux client) — software HEVC on the GPU-less dev
 # box; D3D11VA hardware decode is a follow-up for the real-GPU box.
 ffmpeg-next = "8"