Add validator chain provenance

internal/core/artifacts/artifacts_test.go

@@ -136,12 +136,21 @@ func TestRunManifestIncludesPipelineAndArtifactLaneFields(t *testing.T) {
 				Extractor:  "event-extractor",
 				Merger:     "appendorder",
 				Normalizer: "noop",
-				Validators: []string{"grounded"},
 				Metadata: map[string]any{
 					"extractor": map[string]any{"prompt_id": "test.prompt"},
 				},
 			},
 		},
+		ValidatorChains: []ValidatorChainManifest{
+			{
+				Stage:     "extract",
+				LaneID:    "events",
+				ModuleKey: "event-extractor",
+				Validators: []ValidatorManifest{
+					{Key: "grounded", ExecutionClass: "deterministic"},
+				},
+			},
+		},
 	}
 
 	gotJSON, err := json.Marshal(manifest)
@@ -154,7 +163,7 @@ func TestRunManifestIncludesPipelineAndArtifactLaneFields(t *testing.T) {
 		t.Fatalf("json.Unmarshal() error = %v", err)
 	}
 
-	assertHasKeys(t, got, "pipeline_id", "pipeline_digest", "artifact_lanes", "llm_profiles")
+	assertHasKeys(t, got, "pipeline_id", "pipeline_digest", "artifact_lanes", "validator_chains", "llm_profiles")
 
 	profiles, ok := got["llm_profiles"].([]any)
 	if !ok {
@@ -180,7 +189,20 @@ func TestRunManifestIncludesPipelineAndArtifactLaneFields(t *testing.T) {
 	if !ok {
 		t.Fatalf("artifact_lanes[0] = %#v, want object", lanes[0])
 	}
-	assertHasKeys(t, lane, "id", "extractor", "merger", "normalizer", "validators", "metadata")
+	assertHasKeys(t, lane, "id", "extractor", "merger", "normalizer", "metadata")
+
+	chains, ok := got["validator_chains"].([]any)
+	if !ok {
+		t.Fatalf("validator_chains = %#v, want array", got["validator_chains"])
+	}
+	if len(chains) != 1 {
+		t.Fatalf("len(validator_chains) = %d, want 1", len(chains))
+	}
+	chain, ok := chains[0].(map[string]any)
+	if !ok {
+		t.Fatalf("validator_chains[0] = %#v, want object", chains[0])
+	}
+	assertHasKeys(t, chain, "stage", "lane_id", "module_key", "validators")
 }
 
 func TestRunManifestIncludesReferenceProvenance(t *testing.T) {