This skill should be used when the user says "bug spec", "arness code bug spec", "investigate this bug", "help me debug", "trace this bug", "diagnose this issue", "I found a bug", "something is broken", "why is X not working", "fix this bug", "debug this", "why is this not working", or wants to iteratively investigate a bug through guided conversation with diagnostic analysis. Bridges the gap between a bug report and either a direct fix or a structured bug specification for the Arness pipeline.