feat(windows): pf-vdisplay — all-Rust IddCx virtual display (replaces SudoVDA)

P1 done: a pure-Rust UMDF2 IddCx driver, drop-in compatible with the host's
existing vdisplay/sudovda.rs control plane (the {e5bcc234} interface + the
SudoVDA IOCTL ABI), so the host drives it unchanged. Validated streaming on
glass at 5120x1440@240 — steady 240 fps, ~2.4 ms encode, clean teardown, full
parity with SudoVDA.

- Vendored wdf-umdf-sys / wdf-umdf bindgen crates (MIT, from virtual-display-rs)
  + the SDK-version build.rs fix that resolves the IddCxStub lib path by the WDK
  version actually containing um\x64\iddcx, not the max base SDK.
- pf-vdisplay crate: entry/callbacks/context/control/monitor/edid/
  swap_chain_processor. Our OWN 128-byte EDID (manufacturer PNK, product
  punktfunk — no SudoVDA bytes), a real swap-chain drain (faithful vdd port,
  required so DWM keeps compositing), the SudoVDA-compatible IOCTL control plane
  (ADD/REMOVE/PING/GET_WATCHDOG/GET_VERSION/SET_RENDER_ADAPTER) + a watchdog that
  tears down orphaned monitors when the host stops pinging.
- deploy-dev.ps1: stage + sign + stampinf (date.time DriverVer) + Inf2Cat +
  install, codifying the "bump DriverVer or pnputil keeps the old binary" gotcha.
- docs/windows-virtual-display-rust-port.md: investigation, the on-glass
  validation, and the two traps that cost time (Session-0 measurement +
  accumulated device-state needing a reboot).

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

packaging/windows/vdisplay-driver/pf-vdisplay/src/helpers.rs

@@ -0,0 +1,38 @@
+use std::ops::{Deref, DerefMut};
+
+/// An unsafe wrapper to allow sending across threads
+///
+/// USE WISELY, IT CAN CAUSE UB OTHERWISE
+pub struct Sendable<T>(T);
+unsafe impl<T> Send for Sendable<T> {}
+unsafe impl<T> Sync for Sendable<T> {}
+
+impl<T> Sendable<T> {
+    /// `T` must be Send+Sync safe
+    pub unsafe fn new(t: T) -> Self {
+        Sendable(t)
+    }
+}
+
+impl<T> Deref for Sendable<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<T> DerefMut for Sendable<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+#[macro_export]
+macro_rules! debug {
+    ($($tt:tt)*) => {
+        if cfg!(debug_assertions) {
+            ::log::debug!($($tt)*);
+        }
+    };
+}