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/devtest.rs

@@ -212,6 +212,22 @@ pub fn deck_windows_spike(args: &[String]) -> Result<()> {
     crate::inject::dualsense_windows::deck_spike_hold(0, secs)
 }
 
+/// Windows vmouse SPIKE: hold the pf-mouse virtual HID pointer and sweep the REAL cursor via HID
+/// reports — proves devnode → INF bind → mshidumdf → mouhid → win32k on-glass, and that a resident
+/// virtual pointer makes `SM_MOUSEPRESENT` true (DWM then composites the cursor) with no dongle
+/// attached. Run with the host service STOPPED (the resident mouse owns the mailbox otherwise).
+/// `--seconds N` (default 30).
+#[cfg(target_os = "windows")]
+pub fn vmouse_spike(args: &[String]) -> Result<()> {
+    let secs: u64 = args
+        .iter()
+        .skip_while(|a| *a != "--seconds")
+        .nth(1)
+        .and_then(|s| s.parse().ok())
+        .unwrap_or(30);
+    crate::inject::mouse_windows::spike_hold(secs)
+}
+
 /// Windows: create a virtual DualSense via the UMDF driver (a SwDeviceCreate per-session
 /// devnode plus the shared-memory channel) and hold it, pushing one fixed frame (Cross +
 /// LS-right). Drives the real DualSenseWindowsManager, so it validates the device lifecycle