Unify effective config projection

internal/config/load_validate_test.go

@@ -83,6 +83,42 @@ whisperx:
 	}
 }
 
+func TestEffectivePipelineValuesPreserveNilEmptyAndExactIntegers(t *testing.T) {
+	base := &PipelineConfig{Audita: AuditaConfig{Modules: nil}}
+	nilValues, err := EffectivePipelineValues(base)
+	if err != nil {
+		t.Fatal(err)
+	}
+	base.Audita.Modules = []string{}
+	base.Scriptorium = &ScriptoriumConfig{Artifacts: map[string]ScriptoriumArtifactConfig{
+		"recap": {Vars: map[string]any{"exact": int64(9007199254740993)}},
+	}}
+	emptyValues, err := EffectivePipelineValues(base)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := effectiveValueForTest(t, nilValues, "audita.modules"); got != "null" {
+		t.Fatalf("nil sequence value = %q, want null", got)
+	}
+	if got := effectiveValueForTest(t, emptyValues, "audita.modules"); got != "[]" {
+		t.Fatalf("empty sequence value = %q, want []", got)
+	}
+	if got := effectiveValueForTest(t, emptyValues, "scriptorium.artifacts.recap.vars.exact"); got != "9007199254740993" {
+		t.Fatalf("exact integer value = %q", got)
+	}
+}
+
+func effectiveValueForTest(t *testing.T, values []EffectivePipelineValueRecord, path string) string {
+	t.Helper()
+	for _, value := range values {
+		if value.Path == path {
+			return value.Value
+		}
+	}
+	t.Fatalf("effective value %q not found", path)
+	return ""
+}
+
 func TestValidateMissingAudioSource(t *testing.T) {
 	cfg := loadedValidConfig(t)
 	cfg.Session.Inputs.AudioDir = ""