Memory

How Rust manages memory: where values live, when they're freed, and the allocator interface.

Stack vs Heap	When Rust allocates on the heap, and why it matters
Drop Order	Deterministic destruction, ManuallyDrop, forget
Global Allocator	Custom allocators via #[global_allocator]
Memory Layout	Alignment, padding, repr(C), repr(packed)
Leaks	mem::forget, Rc cycles, when leaking is intentional