More tweaks

Author: kunitoki

guidelines.md

@@ -296,6 +296,7 @@ TEST (ClassNameTests, StaticMethodBehavesCorrectly)
 4. **Group related tests** in test fixtures
 5. **Keep tests independent** and deterministic
 6. **Never Use C or C++ macros (like M_PI)** use yup alternatives
+7. **ALWAYS and EXCLUSIVELY use `just test`** to compile and execute tests
 
 ### When suggesting refactoring:
 1. **Maintain existing API contracts**