observability

WellForge run-trace / observability conventions — the .forge/runs/ trace format that records which agents ran for which feature, their outcomes, drift events, verdicts, and (best effort) token cost. Use whenever a workflow command (orchestrate, implement, eval) runs agents and must record a run, when reading agent run history, when the evaluator needs trajectory evidence, or when $wf-status surfaces recent runs and cost. Canonical reference for the .forge/runs/ schema — producers and consumers MUST follow it.