Refactor CoralSubsystem to remove direct ElevatorSubsystem dependency

[coderabbitai]

Background

Currently, CoralSubsystem directly depends on ElevatorSubsystem through constructor injection:

class CoralSubsystem(private val io: CoralIO, private val elevator: ElevatorSubsystem)

Problem

This creates tight coupling between these subsystems which may not be ideal for the following reasons:

• Makes testing CoralSubsystem in isolation more difficult
• Creates a direct dependency between subsystems that should potentially be independent
• May cause circular dependencies if ElevatorSubsystem ever needs to interact with CoralSubsystem

Potential Solutions

Consider alternatives such as:

• Using an event/message bus for communication between subsystems
• Creating an interface that ElevatorSubsystem implements
• Using a mediator pattern to handle inter-subsystem communication

References

• Discussed in PR Merge competition/mike2 into master #21: Merge competition/mike2 into master #21 (comment)

@Baconing requested this issue to track the concern for future refactoring.