fix(windows-installer): build the gamepad drivers from source in CI too

Fold the pf-dualsense (DualSense / DualShock 4) and pf-xusb (Xbox 360 / XInput)
UMDF drivers into the in-tree drivers workspace (their source had stale
../../crates/wdk-* path-deps from before the wdk vendoring reorg and could no
longer build at all) and build them from source per release, exactly like
pf-vdisplay - same anti-stale reasoning. One `cargo build --release` now builds
all three drivers against the vendored wdk-sys (incl. the bindgen 0.72 pin), and
build-gamepad-drivers.ps1 signs pf_dualsense + pf_xusb (clear FORCE_INTEGRITY ->
sign dll -> stampinf -> Inf2Cat -> sign cat) with one shared cert + .cer,
matching the layout install-gamepad-drivers.ps1 expects. pack-host-installer.ps1
builds + stages them instead of the retired checked-in binaries.

Validated on the runner: the whole workspace (pf-vdisplay + pf-dualsense +
pf-xusb) builds with CARGO_TARGET_DIR=C:\t set, and build-gamepad-drivers.ps1
produces signed pf_dualsense.{dll,inf,cat} + pf_xusb.{dll,inf,cat} + the .cer.

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

packaging/windows/drivers/pf-xusb/pf_xusb.inx

@@ -0,0 +1,64 @@
+;/*++
+; punktfunk virtual Xbox 360 XUSB companion — a non-HID UMDF2 driver that registers the XUSB
+; device-interface GUID {EC87F1E3-...} and answers the buffered XInput IOCTLs, so classic
+; XInputGetState() reads the pad without a kernel bus driver (the HIDMaestro approach). System class,
+; hosted by the in-box WUDFRd reflector. Created per-session by the host via SwDeviceCreate
+; (hardware id `pf_xusb`); `root\pf_xusb` is the devgen/devcon test id.
+;--*/
+[Version]
+Signature   = "$WINDOWS NT$"
+Class       = System
+ClassGuid   = {4D36E97D-E325-11CE-BFC1-08002BE10318}
+Provider    = %ProviderString%
+CatalogFile = pf_xusb.cat
+PnpLockdown = 1
+
+[DestinationDirs]
+DefaultDestDir = 13
+
+[SourceDisksNames]
+1 = %DiskId1%,,,""
+
+[SourceDisksFiles]
+pf_xusb.dll = 1,,
+
+[Manufacturer]
+%StdMfg%=Standard, NT$ARCH$.10.0...22000
+
+[Standard.NT$ARCH$.10.0...22000]
+%DeviceDesc%=pfXusb, root\pf_xusb, pf_xusb
+
+[pfXusb.NT]
+CopyFiles=Drivers_Dir
+Include=WUDFRD.inf
+Needs=WUDFRD.NT
+
+[Drivers_Dir]
+pf_xusb.dll
+
+[pfXusb.NT.HW]
+Include=WUDFRD.inf
+Needs=WUDFRD.NT.HW
+
+[pfXusb.NT.Services]
+Include=WUDFRD.inf
+Needs=WUDFRD.NT.Services
+
+[pfXusb.NT.Wdf]
+UmdfService=pf_xusb, pfXusb_Install
+UmdfServiceOrder=pf_xusb
+UmdfKernelModeClientPolicy=AllowKernelModeClients
+UmdfFileObjectPolicy=AllowNullAndUnknownFileObjects
+UmdfMethodNeitherAction=Copy
+UmdfFsContextUsePolicy=CanUseFsContext2
+UmdfHostProcessSharing=ProcessSharingDisabled
+
+[pfXusb_Install]
+UmdfLibraryVersion=$UMDFVERSION$
+ServiceBinary=%13%\pf_xusb.dll
+
+[Strings]
+ProviderString = "punktfunk"
+StdMfg         = "(Standard system devices)"
+DiskId1        = "punktfunk XUSB Installation Disk"
+DeviceDesc     = "punktfunk Virtual Xbox 360 (XUSB)"