feat(kernel): add PL011 UART console and arch I/O helpers

- Add IOSerial: PL011 (0x0900_0000) TX with FIFO-full polling, yield while waiting
- Add Arch/IO.h (32-bit MMIO with DSB) and Arch/CPU.h (yield, WFI)
- Extend types.h (e.g. ASCII, Address, Int/UInt aliases)
- Wire KernelMain to IOSerialPutString for early boot output
- Drop .sourcekit-lsp config; note IO glob in CMake (commented)

Kernel/Source/KernelMain.c

@@ -1,5 +1,6 @@
-#include "types.h"
+#include <types.h>
+#include <IO/IOSerial.h>
 
 void KernelMain(void) {
-    volatile UInt64 meow = 0x12345;
+    IOSerialPutString("Meow nya!!\n");
 }