feat(host/windows): seal the host↔driver channels (frame + gamepad, proto v2)

Frame ring (pf-vdisplay) and both gamepad SHM channels move off named Global\
objects (openable by any sibling LocalService) to UNNAMED sections/events whose
handles the host DuplicateHandles into the driver's verified WUDFHost with least
access — frame delivery over the SYSTEM+admins-only IOCTL_SET_FRAME_CHANNEL,
pads over a 32-byte named bootstrap mailbox (pid + handle value only, DoS-bounded;
HID minidrivers have no control device). Driver-validated pad_index kills
cross-pad redirects; v1↔v2 mixes fail closed with diagnosis logs on both sides.
Sibling-LocalService denial proven empirically (design/idd-push-security.md,
design/gamepad-channel-sealing.md).

Driver-side raw ops now live behind pf-umdf-util (checked shm accessors, the
forbid(unsafe_code) ChannelClient state machine, WDF request tokens) — the pad
drivers' logic is 100% safe Rust; whole drivers workspace clippy-gated in CI.

driver install --gamepad now sweeps SWD\punktfunk phantom devnodes: a re-created
SwDevice REVIVES the old devnode with its previously-bound driver (never
re-ranks), so an upgrade otherwise leaves the old driver serving — or, across
the v1→v2 fence, a dead pad (found live on the RTX box).

On-glass validated on the RTX 4090 box: frame path 7007 frames p50 2.06 ms
cross-machine; DualSense + XUSB "sealed pad channel mapped"/proto=2 attach via
both the test harness and a real streaming session; phantom-sweep repro.

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

crates/punktfunk-host/src/capture/windows/dxgi.rs

@@ -42,6 +42,10 @@ pub struct WinCaptureTarget {
     pub gdi_name: String,
     /// Stable SudoVDA target id — re-resolved to the current GDI name on every recovery.
     pub target_id: u32,
+    /// The pf-vdisplay driver's WUDFHost pid (from the ADD reply) — the process the IDD-push capturer
+    /// duplicates the sealed frame channel's handles INTO (`idd_push::ChannelBroker`). `0` = unknown
+    /// (a pre-v2 pairing can't occur — the version handshake is hard — so this only guards misuse).
+    pub wudf_pid: u32,
 }
 
 /// A GPU-resident captured texture (future NVENC-D3D11 zero-copy path).