feat(windows): Rust UMDF virtual DualSense driver + shared-memory host channel

A self-authored UMDF2 HID minidriver (packaging/windows/dualsense-driver) that
presents a virtual Sony DualSense (VID 054C/PID 0CE6) on Windows — adaptive
triggers / lightbar / rumble that ViGEm structurally cannot deliver.

Validated live on an RTX box (Win11 25H2, Secure Boot ON): the self-signed driver
loads, Steam recognizes it as a genuine DualSense, and a game's 0x02 output report
reaches the driver. The host<->driver channel is a named shared-memory section
(Global\pfds-shm-<idx>) the host creates and the driver maps from its timer: input
report 0x01 host->driver, output report 0x02 driver->host — input and output proven
both directions live. This bypasses hidclass, which gates both a custom device
interface and custom IOCTLs on the HID node, and UMDF has no control device.

Built in Rust on microsoft/windows-drivers-rs. The load wall was the PE
FORCE_INTEGRITY bit that wdk-build sets via /INTEGRITYCHECK (forces a CI-trusted
page-hash signature a self-signed cert cannot satisfy) — cleared post-build. See
packaging/windows/dualsense-driver/README.md for the build/sign/install recipe.

Deferred: SwDeviceCreate per-session device lifecycle; removing the inert in-driver
IOCTL-channel code; full on-glass session test.

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

packaging/windows/dualsense-driver/Cargo.toml

@@ -0,0 +1,36 @@
+[package]
+edition = "2024"
+name = "pf-dualsense"
+version = "0.1.0"
+publish = false
+license = "MIT OR Apache-2.0"
+description = "punktfunk virtual DualSense UMDF2 HID minidriver (M0 spike)"
+
+[package.metadata.wdk.driver-model]
+driver-type = "UMDF"
+target-umdf-version-minor = 31
+umdf-version-major = 2
+
+[lib]
+crate-type = ["cdylib"]
+
+[build-dependencies]
+wdk-build.path = "../../crates/wdk-build"
+
+[dependencies]
+wdk.path = "../../crates/wdk"
+wdk-sys.path = "../../crates/wdk-sys"
+
+[features]
+default = ["hid"]
+hid = ["wdk-sys/hid"]
+nightly = ["wdk-sys/nightly", "wdk/nightly"]
+
+[profile.dev]
+lto = true
+
+[profile.release]
+lto = true
+
+# Standalone package (not part of the windows-drivers-rs root workspace).
+[workspace]