[FEATURE] Add Digital Output (DO) State Query API for Improved Observability

[zlin-flexiv]

Feature Request: Add Digital Output (DO) State Query API

Background

The current SDK provides APIs to set Digital Outputs (DO), but does not provide a way to query the current DO state.

Problem

In practical applications, especially in distributed systems (e.g., robot + cloud platform + web UI), the lack of DO state query introduces several challenges:

• State inconsistency between the robot controller and external systems
• Difficulty in monitoring and debugging DO-related behaviors
• No reliable way to recover or resynchronize state after disconnection or restart
• Inability to verify whether a DO command has been successfully applied

Proposed Solution

Provide an API to query DO state