fix: replace unbounded strcpy with snprintf to prevent buffer overflow (V-001)

[Senrian]

Summary

Fix CRITICAL severity buffer overflow vulnerability in codes/c/utils/print_util.h.

Vulnerability

Field	Value
ID	V-001
Severity	CRITICAL
File	codes/c/utils/print_util.h:67-68

Issue: strcpy() does not validate that the destination buffer is large enough to hold the source string.

// BEFORE (vulnerable)
trunk->str = (char *)malloc(sizeof(char) * 10);
strcpy(trunk->str, str);  // unbounded copy - buffer overflow if str > 9 chars

// AFTER (safe)
trunk->str = (char *)malloc(sizeof(char) * (strlen(str) + 1));
snprintf(trunk->str, strlen(str) + 1, "%s", str);  // bounded copy with proper sizing

Changes

• Allocate buffer based on actual string length (strlen(str) + 1)
• Replace strcpy with snprintf for bounds-checked copy

Verification

• Build passes
• Code review passed

Closes #1876