go-performancelisted

# Go Performance Performance decisions and optimizations use different evidence loops: `decision: accepted workload -> multiplier or ceiling -> viable mechanisms -> structural acceptance boundary -> planned measurement` `optimization: accepted budget -> comparable baseline -> attribution -> smallest change -> comparable delta` A budget without a unit, percentile, and owner is a mood. Before implementation, reject mechanisms whose amplification or ceiling cannot satisfy the accepted envelope. After implementation, claim an improvement only from comparable measurements under that workload. For a delegated Decision or Review, or when the active artifact requires its result interface, load the [shared specialist contract](../../contracts/specialist-contract.md). Ground every changed mechanism or claim in accepted workloads, SLOs, execution paths, measurements, and rollout constraints. For comparing mechanisms, interacting hot paths, or a decision/review handoff, record `PerformancePath{workload, budget, unit, percentile_or_capacity, multiplier, mechanism, baseline, attribution, delta, owner, proof}` per path. A single local claim can use the existing benchmark result and task artifact; record only the fields applicable to the selected evidence loop. [Benchmarking](../../../docs/benchmarking.md) owns proof level, workload identity, comparable evidence, and completion policy. Load one matching leaf for capture. Read that owner for measurement; the references below cover decis