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

arch/armv8i/linker.ld

@@ -0,0 +1,51 @@
+OUTPUT_FORMAT("elf32-littlearm")
+OUTPUT_ARCH(arm)
+ENTRY(_start)
+
+SECTIONS
+{
+    . = 0x40080000;
+
+    __kernel_start = .;
+
+    .text.boot : {
+        KEEP(*(.text.boot))
+    }
+
+    .vectors : ALIGN(2048) {
+        KEEP(*(.vectors))
+    }
+
+    .text : ALIGN(4096) {
+        *(.text .text.*)
+    }
+
+    .rodata : ALIGN(4096) {
+        *(.rodata .rodata.*)
+    }
+
+    .data : ALIGN(4096) {
+        *(.data .data.*)
+    }
+
+    .bss : ALIGN(4096) {
+        __bss_start = .;
+        *(.bss .bss.*)
+        *(COMMON)
+        . = ALIGN(4096);
+        __bss_end = .;
+    }
+
+    .stack : ALIGN(4096) {
+        . += 0x4000; /* 16 KB IRQ Stack */
+        irq_stack_top = .;
+        . += 0x2000; /* 8 KB ABT Stack */
+        abt_stack_top = .;
+        . += 0x2000; /* 8 KB UND Stack */
+        und_stack_top = .;
+        . += 0x10000; /* 64 KB SVC Kernel Stack */
+        stack_top = .;
+    }
+
+    __kernel_end = .;
+}