Feature: Map INAV Health States to DroneCAN NodeStatus

[daijoubu]

Summary

Enhance DroneCAN NodeStatus messaging to broadcast actual INAV health and mode information instead of static OK/OPERATIONAL values.

Current State

The DroneCAN driver currently broadcasts static health status (OK) and operational state (OPERATIONAL) with a hardcoded vendor code (1234). This doesn't provide real health telemetry.

Proposed Solution

1. Map INAV health states and modes to NodeStatus fields
2. Encode vendor-specific data with:
   • GPS status/lock quality
   • Battery state (voltage, SOC if available)
   • RSSI/signal strength

Impact

• Real-time health monitoring via DroneCAN
• Better diagnostics during flight
• Improved integration with other DroneCAN nodes

Priority

HIGH - Identified in DroneCAN roadmap investigation

Related

• DroneCAN Battery SOC support (Feature: Add DroneCAN Battery SOC support #3)
• DroneCAN DNA server (Feature: DroneCAN DNA (Dynamic Node Allocation) Server #4)

[daijoubu]

Closed in PR #13