afa9d4aa46
Snapshot of FFI progress mid-M4. Allocator-aware sx-defined-class lifecycle is done end-to-end (state struct + +alloc + -dealloc). Stdlib NSObject + autoreleasepool helper landed; defer-release pattern works at user code. Property ARC ops (M4.B) is the next slice. 185/185 example tests pass; chess on iOS-sim regression-verified at every M4 sub-commit.