# Decision: APPROVE ✅

## Summary
SmallString optimization has been successfully implemented and validated. All 377 tests pass, including 7 acceptance criteria and 9 additional edge case tests. Code review approved with no blocking issues.

## Results
- **Tests**: All 377 passed ✅
- **Acceptance Criteria**: All 7 met ✅
  1. SmallString enum created with Inline/Heap variants
  2. new(), push_str(), as_str() methods implemented
  3. Heap promotion at 23-byte boundary verified
  4. VM.stdout changed to SmallString
  5. VM::new() initializes with SmallString::new()
  6. format_output() uses as_str()
  7. All print-related tests pass

- **Code Review**: Approved with no blocking issues ✅

## Non-Blocking Items (Tracked as Debt)
These are optional improvements that do not affect approval:

1. **UTF-8 Validation** (lines 54-55, 72-73): Consider using unwrap_or_default() or documenting why .expect() panics are acceptable for this internal implementation
2. **Allocation Profiling**: Add benchmarks to empirically verify the claimed elimination of 1-2 heap allocations per print operation
3. **Debug Assertions**: Add assertions to enforce the Inline variant's len ≤ 23 invariant

## Next Steps
Ready for merge. Debt items can be addressed in a follow-up optimization task if desired.
