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>

crates/punktfunk-host/src/main.rs

@@ -279,6 +279,10 @@ fn real_main() -> Result<()> {
         // Windows N4 SPIKE: hold a software-devnode HID Steam Deck and watch Steam Input promote it.
         #[cfg(target_os = "windows")]
         Some("deck-windows-spike") => devtest::deck_windows_spike(&args),
+        // Windows: hold the pf-mouse virtual HID pointer and sweep the real cursor via HID reports
+        // (validates the resident-mouse cursor-presence fix on-glass). `--seconds N`.
+        #[cfg(target_os = "windows")]
+        Some("vmouse-spike") => devtest::vmouse_spike(&args),
         // Windows: create a virtual DualSense (or --ds4/--edge/--deck/--xbox) via the UMDF driver and
         // hold it, driving the real *WindowsManager end to end. `--index N`, `--seconds N`.
         #[cfg(target_os = "windows")]