deep_equal.ts

Deep equality comparison that checks both structure and type.

Key behaviors:

- Compares by constructor to prevent type confusion (security: {} ≠ [], {} ≠ new Map(), new ClassA() ≠ new ClassB()) - Prevents asymmetry bugs: deep_equal(a, b) always equals deep_equal(b, a) - Compares only enumerable own properties (ignores prototypes, symbols, non-enumerable) - Special handling for: Date (timestamp), Number/Boolean (boxed primitives), Error (message/name) - Promises always return false (cannot be meaningfully compared) - Maps/Sets compare by reference for object keys/values