Implement Basic Fault Manager Node #76
Description
Summary
Central fault manager node: receives reports, stores in-memory, provides query interface.
Proposed solution (optional)
ROS 2 node with:
- Service server: ReportFault
- Service server: GetFaults
- Service server: ClearFault
- In-memory storage (std::map<fault_code, FaultState>)
No filtering, no persistence yet - just skeleton.
Additional context (optional)
Track per-fault: occurrence_count, reporting_sources
Aggregates by fault_code (same code from different sources = one fault)