goal-evidence-ledgerlisted

# Goal Evidence Ledger ## Contract Iron law: no AC transitions to `pass` without a FlowEvidence sidecar whose `proves: [<AC.id>]` names it, and every non-trivial sidecar declares what it does NOT prove. Invoked by `goal-evaluator` (Step 2, once per verification command), by `/flow:start` Phase 4 and `/flow:address` (verification-evidence sidecars on the FlowRun), and by `/flow:goal evaluate` for judge reports. Inputs: evidence id, type, proves list, and optional command, exit code, raw-output path, limitations, negative cases. Returns the sidecar path, which the caller sets as the AC's `evidence_ref`. Permitted skips: `limitations` on `holdout_validation` and `verdict` types; the raw `.txt` when nothing was captured. The helper is never skipped. ## Inputs 1. **Evidence id** — `evidence-<AC.id>-<descriptor>-<turn>`; lowercase, digits, `_-`. 2. **Evidence type** — one of `evidence.schema.json`'s enum: command_result, test_result, lint_result, runtime_smoke_result, visual_result, git_diff, holdout_validation, verdict, human_approval, review_comment_snapshot, ci_status, llm_judge_report, artifact_check, path_boundary_check. 3. **Proves** — AC ids this evidence supports. 4. Optional: `command`, `exit_code`, raw output path, `limitations`, `negative_cases`. ## Outputs 1. `.flow/runs/<run-id>/evidence/<evidence-id>.evidence.yaml` (schema `plugins/flow/schemas/v1/evidence.schema.json`). 2. `.flow/runs/<run-id>/evidence/<evidence-id>.txt` — raw stdout/stderr when captured. 3. An