feat: Implement modern Tree directory visualizer, TSC profiler, and VT Art visualizer

- Add dedicated Linux-compatible Tree visualizer with UTF-8/ASCII branch tracking, -L depth filtering, human sizes, and permissions in userland/lazybox/tree.c
- Implement Hardware Invariant Timestamp Counter (TSC) calibration and microsecond delay timer in kernel/tsc.c and include/kernel/tsc.h
- Add Virtual Terminal color palette, live resource utilization bars, and logo banner in kernel/vt_art.c and include/kernel/vt_art.h
- Add LazyBox applets: 'tree', 'tscinfo', and 'vtart'
- Update README.md documentation and command matrix

include/kernel/vt_art.h

@@ -0,0 +1,10 @@
+#ifndef _KERNEL_VT_ART_H
+#define _KERNEL_VT_ART_H
+
+#include <stdint.h>
+
+void vt_show_palette_256(void);
+void vt_show_load_bars(uint32_t cpu_percent, uint32_t mem_percent, uint32_t disk_percent);
+void vt_show_logo_banner(void);
+
+#endif // _KERNEL_VT_ART_H