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/src/audio.rs

@@ -18,7 +18,7 @@ use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::mpsc::{Receiver, SyncSender, TrySendError};
 use std::sync::Arc;
 use std::time::Duration;
-use wasapi::{Direction, SampleType, StreamMode, WaveFormat};
+use wasapi::{DeviceEnumerator, Direction, SampleType, StreamMode, WaveFormat};
 
 const SAMPLE_RATE: usize = 48_000;
 const CHANNELS: usize = 2;
@@ -97,8 +97,10 @@ fn render_thread(
         return Ok(());
     }
     let res = (|| -> Result<()> {
-        let device =
-            wasapi::get_default_device(&Direction::Render).context("default render endpoint")?;
+        let device = DeviceEnumerator::new()
+            .context("DeviceEnumerator")?
+            .get_default_device(&Direction::Render)
+            .context("default render endpoint")?;
         let mut audio_client = device.get_iaudioclient().context("IAudioClient")?;
         let desired = WaveFormat::new(32, 32, &SampleType::Float, SAMPLE_RATE, CHANNELS, None);
         let (default_period, _min_period) =
@@ -159,7 +161,7 @@ fn render_thread(
                 primed = false;
             }
             render_client
-                .write_to_device(avail_frames, BLOCK_ALIGN, &out, None)
+                .write_to_device(avail_frames, &out, None)
                 .context("write_to_device")?;
         }
         audio_client.stop_stream().ok();
@@ -219,7 +221,9 @@ fn mic_thread(connector: &Arc<NativeClient>, stop: Arc<AtomicBool>) -> Result<()
     .map_err(|e| anyhow!("opus encoder: {e}"))?;
     let _ = encoder.set_bitrate(opus::Bitrate::Bits(64_000));
 
-    let device = wasapi::get_default_device(&Direction::Capture)
+    let device = DeviceEnumerator::new()
+        .context("DeviceEnumerator")?
+        .get_default_device(&Direction::Capture)
         .context("default capture endpoint (no microphone?)")?;
     let mut audio_client = device.get_iaudioclient().context("IAudioClient")?;
     let desired = WaveFormat::new(32, 32, &SampleType::Float, SAMPLE_RATE, CHANNELS, None);