implement proper IRQL, DPCs, kernel and user APCs, alertable waits, async file I/O with cancellation, trap frames, selftests, a real driver/device model, native async FAT32, VFAT dotfile fixes, syscall ABI cleanup, async_apc and async_cancel tests, POSIX multi-volume paths, and pimp the readme.

code/kernel/ke_selftest.h

@@ -0,0 +1,9 @@
+#pragma once
+// ke_selftest.h - temporary kernel bring-up self-tests.
+//
+// These tests intentionally live behind one call site so they can be walled
+// off or compiled out later without touching kmain.c again.
+
+#include <hal_api.h>
+
+void KiRunKernelSelfTests(const HAL_API* hal);