[idd] input: preserve reports under backpressure

Move named pipe writes off the LGMP input worker so a stalled LGInput
endpoint cannot block queue draining or lease maintenance.

Coalesce motion only under queue pressure while preserving mode, button,
wheel, and keyboard transitions. Reset HID state after discontinuities
and carry all 32 mouse button bits through the pipe and HID reports.

idd/LGCommon/CPipeEndpoint.h

@@ -128,4 +128,5 @@ private:
   HANDLE m_pipe = INVALID_HANDLE_VALUE;
   HANDLE m_thread = nullptr;
   HANDLE m_stopEvent = nullptr;
+  HANDLE m_writeEvent = nullptr;
 };