feat(windows-drivers): STEP 3 on-glass — driver LOADS + runs full IddCx init chain

Major on-glass progress on the RTX box. The all-Rust wdk-sys IddCx driver now LOADS
under Secure Boot and runs the ENTIRE init chain: DriverEntry -> WdfDriverCreate ->
driver_add -> IddCxDeviceInitConfig(0x0) -> WdfDeviceCreate -> CreateDeviceInterface
-> IddCxDeviceInitialize -> D0Entry -> init_adapter. Findings:
- Signing was a RED HERRING (the driver loads); std works in WUDFHost (DualSense uses
  it too).
- THE unblock: link the iddcx **1.10** IddCxStub (build.rs now picks the highest
  version-aware), not 1.0 — the 1.0 stub lacks the version-table symbols AND its
  dispatch table mismatched the 1.10 framework, which made IddCxDeviceInitConfig
  return INVALID_PARAMETER. With 1.10 the whole chain runs.
- Added a file/OutputDebugString logger (log.rs, matches the DualSense driver) — the
  driver was silent; this is how the chain was traced.
- size.rs: framework_struct_size() reads the frameworks authoritative struct sizes
  from IddStructures[] (the config keeps size_of=208, validated working).
- adapter.rs: version ptrs + ObjectAttributes(InheritFromParent) + FP16 + framework
  caps/diag/version sizes — matches the oracle.

KNOWN WIP: IddCxAdapterInitAsync still returns INVALID_PARAMETER though caps match
the framework size table (88/56/24) + the oracle exactly — likely a subtle wdk-sys
bindgen field-layout detail in IDDCX_ADAPTER_CAPS/IDDCX_ENDPOINT_DIAGNOSTIC_INFO.
CI gate (compile+link) stays green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packaging/windows/drivers/pf-vdisplay/src/log.rs

@@ -0,0 +1,26 @@
+//! Minimal driver logger (matches the DualSense driver). DebugView can't capture the UMDF host across
+//! session 0, so besides `OutputDebugStringA` we append to a world-writable file readable over SSH. Used
+//! only for bring-up/diagnostics; cheap and best-effort (ignores all errors).
+
+unsafe extern "system" {
+    fn OutputDebugStringA(s: *const u8);
+}
+
+pub fn log(s: &str) {
+    if let Ok(c) = std::ffi::CString::new(s) {
+        // SAFETY: `c` is a valid NUL-terminated string for the duration of the call.
+        unsafe { OutputDebugStringA(c.as_ptr().cast()) };
+    }
+    use std::io::Write;
+    if let Ok(mut f) = std::fs::OpenOptions::new()
+        .create(true)
+        .append(true)
+        .open("C:\\Users\\Public\\pfvd-driver.log")
+    {
+        let _ = writeln!(f, "{s}");
+    }
+}
+
+macro_rules! dbglog {
+    ($($a:tt)*) => { $crate::log::log(&::std::format!($($a)*)) };
+}