Refactoring Patterns

<default_to_action> When refactoring:

1. ENSURE tests pass (never refactor without tests)
2. MAKE small change (one refactoring at a time)
3. RUN tests (must stay green)
4. COMMIT (save progress)
5. REPEAT

Safe Refactoring Cycle:

npm test               # Green ✅
# Make ONE small change
npm test               # Still green ✅
git commit -m "refactor: extract calculateTotal"
# Repeat