Add extract worker configuration controls

internal/core/config/effective_config_test.go

@@ -27,6 +27,19 @@ func TestResolveRejectsEmptyAndUnknownPipelineID(t *testing.T) {
 	}
 }
 
+func TestResolveMaterializesDefaultExtractWorkersFromEffectiveTotal(t *testing.T) {
+	cfg := validConfig()
+	cfg.Concurrency.TotalLLM = 4
+
+	effective, err := cfg.Resolve(ResolveInput{PipelineID: "example", Catalog: fakeCatalog(t)})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v, want nil", err)
+	}
+	if got := effective.Config.Concurrency.StageWorkers["extract"]; got != 4 {
+		t.Fatalf("effective extract workers = %d, want total concurrency 4", got)
+	}
+}
+
 func TestResolveLaneFilteringSuccessAndFailure(t *testing.T) {
 	effective, err := validConfig().Resolve(ResolveInput{
 		PipelineID: " example ",