feat(host/windows): resident virtual HID mouse (pf-mouse UMDF minidriver)

Headless Windows hosts (no dongle) stream an INVISIBLE cursor: with no
pointing device present win32k reports SM_MOUSEPRESENT=0 and DWM never
composites a pointer into the pf-vdisplay frame, even though SendInput
moves it. Keep ONE virtual HID mouse devnode alive for the host's
lifetime — the Sunshine/Parsec-class fix, zero client changes.

- pf-mouse: UMDF2 HID minidriver, one fixed identity (PF:MO 5046:4D4F,
  obviously virtual, nothing fingerprints it), one 8-byte input report
  (5 buttons + absolute 15-bit X/Y + wheel + AC-pan). Transport is the
  sealed pad channel verbatim (Global\pfmouse-boot-0 mailbox + unnamed
  MouseShm DATA section) so pf-umdf-util's audited layer serves it
  unchanged; report delivery is event-driven (idle = no HID traffic).
- host: inject::mouse_windows — VirtualMouse (SwDeviceCreate'd devnode +
  channel), ensure_resident() keeper thread started by every
  InjectorService (process-wide, PUNKTFUNK_NO_VIRTUAL_MOUSE opts out),
  vmouse-spike on-glass validation (cursor sweep via HID reports).
- proto: mouse module (magic, boot-name, identity, report layout,
  unit-tested input_report packing).
- SwDeviceProfile grows container_tag so the mouse's ContainerId family
  (PFMO) never groups with a pad's (PFDS) in the Devices UI.
- packaging: pf-mouse rides the gamepad-driver build + install pipeline
  (build-gamepad-drivers.ps1, windows-drivers.yml, driver install
  --gamepad picks up every staged .inf).

On-glass validated on winbox: devnode + HID child bind, SM_MOUSEPRESENT=1
with no physical mouse, cursor sweeps via HID reports (vmouse-spike).

This work was implemented in a parallel session; committed here as the
build prerequisite for the HID compose kick that follows.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packaging/windows/drivers/pf-mouse/pf_mouse.inx

@@ -0,0 +1,79 @@
+;/*++
+; punktfunk virtual HID mouse (absolute pointer) — UMDF2 HID minidriver INF.
+; Same skeleton as pf_dualsense.inx (the WDK vhidmini2 UMDF2 shape).
+; Depends on MsHidUmdf.inf (build >= 22000).
+; Install: devgen /add /hardwareid "root\pf_mouse"  (after pnputil /add-driver /install)
+;--*/
+[Version]
+Signature="$WINDOWS NT$"
+Class=HIDClass
+ClassGuid={745a17a0-74d3-11d0-b6fe-00a0c90f57da}
+Provider=%ProviderString%
+CatalogFile=pf_mouse.cat
+PnpLockdown=1
+
+[DestinationDirs]
+DefaultDestDir = 13
+
+[SourceDisksNames]
+1=%Disk_Description%,,,
+
+[SourceDisksFiles]
+pf_mouse.dll=1
+
+[Manufacturer]
+%ManufacturerString%=pf, NT$ARCH$.10.0...22000
+
+[pf.NT$ARCH$.10.0...22000]
+; Hardware ids: `root\pf_mouse` for a root-enumerated devnode (devgen/devcon tests); `pf_mouse` for
+; the host's SwDeviceCreate'd resident pointer (the `root\` prefix is reserved for root enumeration,
+; so SwDeviceCreate rejects it with E_INVALIDARG).
+%DeviceDesc%=pfMouse, root\pf_mouse, pf_mouse
+
+[pfMouse.NT]
+CopyFiles=UMDriverCopy
+Include=MsHidUmdf.inf
+Needs=MsHidUmdf.NT
+Include=WUDFRD.inf
+Needs=WUDFRD_LowerFilter.NT
+
+[pfMouse.NT.hw]
+Include=MsHidUmdf.inf
+Needs=MsHidUmdf.NT.hw
+Include=WUDFRD.inf
+Needs=WUDFRD_LowerFilter.NT.hw
+
+[pfMouse.NT.Services]
+Include=MsHidUmdf.inf
+Needs=MsHidUmdf.NT.Services
+Include=WUDFRD.inf
+Needs=WUDFRD_LowerFilter.NT.Services
+
+[pfMouse.NT.Filters]
+Include=WUDFRD.inf
+Needs=WUDFRD_LowerFilter.NT.Filters
+
+[pfMouse.NT.Wdf]
+UmdfService="pf_mouse", pf_mouse_Install
+UmdfServiceOrder=pf_mouse
+UmdfKernelModeClientPolicy=AllowKernelModeClients
+UmdfFileObjectPolicy=AllowNullAndUnknownFileObjects
+UmdfMethodNeitherAction=Copy
+UmdfFsContextUsePolicy=CanUseFsContext2
+; Its own WUDFHost so the driver's per-device statics never collide with a gamepad's (parity with
+; the pad INFs — and the resident mouse outlives any session, so isolation is cheap insurance).
+UmdfHostProcessSharing=ProcessSharingDisabled
+
+[pf_mouse_Install]
+UmdfLibraryVersion=$UMDFVERSION$
+ServiceBinary="%13%\pf_mouse.dll"
+
+[UMDriverCopy]
+pf_mouse.dll
+
+[Strings]
+ProviderString     ="punktfunk"
+ManufacturerString ="punktfunk"
+ClassName          ="HID device"
+Disk_Description   ="punktfunk Mouse Installation Disk"
+DeviceDesc         ="punktfunk Virtual Mouse"