19 tests covering the persistence layer: field round-trip for successful and failed traces (hops, RTT, tx_power, timestamp), recent_traces ordering/limit/target filtering, all_traces cross-target span, traced_targets count-ordering, latest_trace success_only variants, and full run lifecycle (start → finish, error without summary, limit, ordering). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>