Implement Buddy Allocator for Physical Memory Management

Implement buddy system allocator for physical memory.

Requirements:

• Define Block structure with size, status, next pointer
• Maintain array of free lists (one per power-of-2 size)
• Implement buddy_alloc(size) to allocate memory
• Implement buddy_free(ptr) to free memory
• Implement buddy_find_buddy(ptr) to find buddy block
• Implement buddy_coalesce(ptr) to merge with buddy if free
• Support memory sizes from 1 KB to 1024 KB (powers of 2)
• Print allocation, splitting, and coalescing events
• Handle out-of-memory conditions
• Track allocated blocks and free blocks
• Demonstrate with example allocation pattern