feat(sub-lang): Integrate SUB Language (.sb) native kernel modules and in-kernel VM/interpreter

- Add native .sb kernel modules in sub/ (signature.sb, power_governor.sb, benchmark.sb, easter_egg.sb)
- Implement in-kernel SUB Language VM and AST interpreter in kernel/sub/sub_vm.c
- Implement C-interop runtime in kernel/sub/sub_runtime.c and include/kernel/sub_lang.h
- Initialize SUB Language Engine in boot sequence step [8/14] in kernel/main.c
- Implement strtol in lib/string.c
- Add LazyBox applets: 'subinfo', 'subi', 'subpower', 'subbench', and 'subquote'

sub/easter_egg.sb

@@ -0,0 +1,18 @@
+// Interactive Easter Eggs & SUB Kernel Quotes
+// Written in SUB Language (.sb) - Simple Universal Builder
+
+function get_easter_egg(idx) {
+    if idx == 0 {
+        return "SUB-OS: Where C, Assembly, Rust, and SUB-Lang converge."
+    }
+    if idx == 1 {
+        return "Simple Universal Builder: One language to build them all."
+    }
+    if idx == 2 {
+        return "Born from bare-metal, forged in code."
+    }
+    if idx == 3 {
+        return "Memory safety with Rust, native power with C, custom signature with SUB-Lang!"
+    }
+    return "Antigravity + Subhobhai = Infinite Operating System Possibilities."
+}