feat(arch): Add armv8i (32-bit ARM/AArch32) architecture & complete TUI configurator

- Support ARMv8i / ARM32 (AArch32) baremetal target with arm-linux-gnueabihf toolchain
- Implement ARMv8i boot entry point, banked exception mode stacks (IRQ, ABT, UND, SVC)
- Implement 8 exception vectors, GICv2 distributor/CPU interface, CP15 Generic Timer (100 Hz), flat Section MMU
- Support PL011 UART for early console & interactive LazyBox TTY input
- Update Makefile with make armv8i_defconfig and automated cross-compilation
- Update scripts/kconfig/menuconfig.py with dedicated armv8i options

include/arch/armv8i/arch.h

@@ -0,0 +1,23 @@
+#ifndef _ARCH_ARMV8I_ARCH_H
+#define _ARCH_ARMV8I_ARCH_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#define ARMV8I_PAGE_SIZE 4096
+
+// Mode bits in CPSR
+#define CPSR_MODE_USR 0x10
+#define CPSR_MODE_FIQ 0x11
+#define CPSR_MODE_IRQ 0x12
+#define CPSR_MODE_SVC 0x13
+#define CPSR_MODE_MON 0x16
+#define CPSR_MODE_ABT 0x17
+#define CPSR_MODE_HYP 0x1A
+#define CPSR_MODE_UND 0x1B
+#define CPSR_MODE_SYS 0x1F
+
+#define CPSR_IRQ_DISABLE (1 << 7)
+#define CPSR_FIQ_DISABLE (1 << 6)
+
+#endif // _ARCH_ARMV8I_ARCH_H