Add the NXTRX4 communications service

[OrenRotaru]

Summary

This adds one communications service for both NXTRX4 radios. It receives CSP traffic from the uplink radio over I2C, forwards GraphQL and UDP messages to the correct KubOS service, and sends responses and other downlinks through the downlink radio. Large messages use CSP SFP fragmentation and reassembly.

It also adds radio health and control operations to GraphQL, service configuration and telemetry, updates the CSP and SpacePacket libraries for the new traffic path, and includes OBC test tools for radio commands, CSP address scans, I2C checks, packaging, and deployment.

Why

The OBC needs one configurable service that owns the complete ground-to-spacecraft communications path and provides repeatable tools for testing it on hardware.

Impact

Developers can configure and run the new comms service, inspect both radios through GraphQL, and exercise the full uplink and downlink path with the included OBC tests.

Checks

• cargo test -p comms-services — 13 passed
• Bash syntax checks passed for the OBC test scripts
• Python syntax checks passed for the I2C helper scripts
• The Expect-based transfer script was not executed because Expect/Tcl is not installed locally