test(cacache): add comprehensive tests for cacache utilities

- Add 54 new tests covering all cacache wrapper functions
- Test getCacache(), put(), get(), remove(), safeGet(), clear(), withTmp()
- Test wildcard validation and error handling
- Test pattern matching for prefix-based clearing
- Test ENOTEMPTY error handling
- Test integration workflows (put → get → remove)
- Test edge cases: empty keys, long keys, special chars, buffers
- Test concurrent operations
- Code coverage: 75.39% → 75.78% (+0.39pp)
- Cumulative coverage: 86.05% → 86.24%

Author: jdalton