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/build.rs

@@ -7,15 +7,18 @@ fn main() -> Result<(), wdk_build::ConfigError> {
     Ok(())
 }
 
-/// Link `IddCxStub.lib`. It ships only under the SDK *version* that includes IddCx, at
-/// `Lib\<ver>\um\<arch>\iddcx\<iddcxver>\` — a newer base SDK alongside it lacks the `iddcx` subdir, so
-/// glob for the dir that actually contains the lib rather than trusting the max SDK version. x64 only.
+/// Link `IddCxStub.lib`. It ships under `Lib\<sdkver>\um\<arch>\iddcx\<iddcxver>\`, and the iddcx
+/// versions are NOT equivalent: the `1.0`/`1.2` stubs lack the versioned-struct-size table symbols
+/// (`IddStructures`/`IddStructureCount`/`IddClientVersionHigherThanFramework`) that `size.rs` needs —
+/// `1.3`+ and `1.10` have them. So pick the HIGHEST `iddcx\<X.Y>` dir that has the lib (version-aware,
+/// since "1.10" < "1.2" lexically). x64 only.
 fn link_iddcx_stub() {
     const ARCH: &str = "x64";
     const ROOTS: [&str; 2] = [
         r"C:\Program Files (x86)\Windows Kits\10\Lib",
         r"C:\Program Files\Windows Kits\10\Lib",
     ];
+    let mut best: Option<((u32, u32), std::path::PathBuf)> = None;
     for root in ROOTS {
         let Ok(versions) = std::fs::read_dir(root) else {
             continue;
@@ -26,13 +29,24 @@ fn link_iddcx_stub() {
                 continue;
             };
             for sub in subdirs.flatten() {
-                if sub.path().join("IddCxStub.lib").is_file() {
-                    println!("cargo:rustc-link-search={}", sub.path().display());
-                    println!("cargo:rustc-link-lib=static=IddCxStub");
-                    return;
+                if !sub.path().join("IddCxStub.lib").is_file() {
+                    continue;
+                }
+                let name = sub.file_name().to_string_lossy().into_owned();
+                let mut parts = name.split('.');
+                let v = (
+                    parts.next().and_then(|x| x.parse().ok()).unwrap_or(0u32),
+                    parts.next().and_then(|x| x.parse().ok()).unwrap_or(0u32),
+                );
+                if best.as_ref().is_none_or(|(bv, _)| v > *bv) {
+                    best = Some((v, sub.path()));
                 }
             }
         }
     }
-    panic!("IddCxStub.lib not found under any Windows Kits Lib\\<ver>\\um\\{ARCH}\\iddcx\\<iddcxver>\\");
+    let Some((_, dir)) = best else {
+        panic!("IddCxStub.lib not found under any Windows Kits Lib\\<ver>\\um\\{ARCH}\\iddcx\\<iddcxver>\\");
+    };
+    println!("cargo:rustc-link-search={}", dir.display());
+    println!("cargo:rustc-link-lib=static=IddCxStub");
 }