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/Include/Arch/CPU.h

@@ -0,0 +1,9 @@
+#pragma once
+
+static inline void CPUYield() {
+    __asm__ volatile ("yield" ::: "memory");
+}
+
+static inline void CPUWaitForInterrupt() {
+    __asm__ volatile ("wfi" ::: "memory");
+}

Kernel/Include/Arch/IO.h

@@ -0,0 +1,14 @@
+#pragma once
+#include <types.h>
+
+static inline void IOAddressWrite32(UInt64 address, UInt32 value) {
+    __asm__ volatile ("dsb sy" ::: "memory"); // wait till all previous writes are finished physically
+    *(volatile UInt32*)address = value;
+    __asm__ volatile ("dsb sy" ::: "memory"); // wait till my write is finished physically
+}
+
+static inline UInt32 IOAddressRead32(UInt64 address) {
+    UInt32 value = *(volatile UInt32*)address;
+    __asm__ volatile ("dsb ld" ::: "memory"); // wait till my read is finished physically
+    return value;
+}