Establish Standard Unit Testing

[markpete]

The src/test directory is empty/missing, meaning there are no standard unit tests. A src/main/java/frc/robot/test directory exists but seems to contain robot code, not tests.

Action Items:
Create a standard src/test/java directory structure.
Add a testing framework (JUnit 5, Mockito).
Write unit tests for complex logic, particularly in SuperStructure and Controls (after refactoring).