Write workspace checkpoints during runs

internal/framework/pipeline/runner_test.go

@@ -992,6 +992,37 @@ func TestRunPassesChunkContentAndMediaTypeToExtractors(t *testing.T) {
 	}
 }
 
+func TestRunDoesNotPassCheckpointPathsToModules(t *testing.T) {
+	modules := defaultRunnerModules()
+
+	_, err := New(newRunnerRegistries(t, modules)).Run(context.Background(), RunInput{
+		Pipeline:    resolvedPipeline(),
+		Checkpoints: NoopCheckpointRecorder(),
+	})
+	if err != nil {
+		t.Fatalf("Run() error = %v, want nil", err)
+	}
+
+	for _, req := range modules.input.requests {
+		assertNoCheckpointMetadata(t, req.Metadata)
+	}
+	for _, req := range modules.chunker.requests {
+		assertNoCheckpointMetadata(t, req.Metadata)
+	}
+	for _, req := range modules.extractors["extract-alpha"].requests {
+		assertNoCheckpointMetadata(t, req.Metadata)
+	}
+	for _, req := range modules.mergers["merge"].requests {
+		assertNoCheckpointMetadata(t, req.Metadata)
+	}
+	for _, req := range modules.normalizers["normalize"].requests {
+		assertNoCheckpointMetadata(t, req.Metadata)
+	}
+	for _, req := range modules.output.requests {
+		assertNoCheckpointMetadata(t, req.Metadata)
+	}
+}
+
 func TestRunOmitsRejectedExtractOutputsFromMerge(t *testing.T) {
 	modules := defaultRunnerModules()
 	validator := &runnerChainValidator{name: "chain-extract", approved: []bool{false, true}, reason: "bad_extract", message: "extract rejected"}
@@ -2181,6 +2212,25 @@ func warningReasons(warnings []contracts.Warning) []string {
 	return reasons
 }
 
+func assertNoCheckpointMetadata(t *testing.T, metadata map[string]any) {
+	t.Helper()
+
+	for key, value := range metadata {
+		lowerKey := strings.ToLower(key)
+		if strings.Contains(lowerKey, "checkpoint") || strings.Contains(lowerKey, "workspace") {
+			t.Fatalf("metadata key %q exposes checkpoint/workspace state", key)
+		}
+		text, ok := value.(string)
+		if !ok {
+			continue
+		}
+		lowerValue := strings.ToLower(text)
+		if strings.Contains(lowerValue, "checkpoint") || strings.Contains(lowerValue, "workspace") {
+			t.Fatalf("metadata value for %q exposes checkpoint/workspace state: %q", key, text)
+		}
+	}
+}
+
 func assertRunError(t *testing.T, err error, want string) {
 	t.Helper()