feat(host/windows): ViGEm rumble back-channel + Windows clippy clean

Wire the host→client rumble path on Windows, the analogue of the Linux
uinput EV_FF read loop: a game's force-feedback on the virtual Xbox 360
pad is delivered by ViGEm's notification API (`request_notification` →
`spawn_thread`, gated by the crate's `unstable_xtarget_notification`
feature). A per-pad background thread stores the latest motor levels;
`pump_rumble` relays changes to the client on the universal 0xCA plane
(motors scaled 0..255 → 0..65535). Dropping the target aborts the
notification, so the thread exits with the session. Live verification
still needs a physical pad.

Also fix the Windows backends' clippy debt — these modules are cfg-
excluded from Linux CI, so `clippy -D warnings` never saw them, and the
VM's rustc 1.96 clippy is stricter on shared code than the CI image:
- dxgi: manual checked division → checked_div().map_or
- sendinput: `x = x | y` → `x |= y`
- sudovda: `.then(|| ptr)` → `.then_some(ptr)`
- m3 pick_compositor: drop the needless early return (match form)
- m3 resolve_compositor: Windows arm is a tail expr, not `return`

All Windows backends now build + clippy clean (default and --features
nvenc); Linux unaffected (fmt/clippy/check green).

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

crates/punktfunk-host/src/vdisplay/sudovda.rs

@@ -78,8 +78,8 @@ struct RemoveParams {
 /// One `DeviceIoControl` round trip (METHOD_BUFFERED). `input`/`output` may be empty.
 unsafe fn ioctl(h: HANDLE, code: u32, input: &[u8], output: &mut [u8]) -> Result<u32> {
     let mut returned = 0u32;
-    let inp = (!input.is_empty()).then(|| input.as_ptr() as *const c_void);
-    let outp = (!output.is_empty()).then(|| output.as_mut_ptr() as *mut c_void);
+    let inp = (!input.is_empty()).then_some(input.as_ptr() as *const c_void);
+    let outp = (!output.is_empty()).then_some(output.as_mut_ptr() as *mut c_void);
     DeviceIoControl(
         h,
         code,