refactor: move task_fn into its own crate

benches/realistic/etl.rs

@@ -1,8 +1,8 @@
 //! ETL (Extract, Transform, Load) pipeline benchmark
 
 use criterion::{BenchmarkId, Criterion};
-use dagx::{task_fn, DagRunner, TaskHandle};
-
+use dagx::{DagRunner, TaskHandle};
+use dagx_test::task_fn;
 pub fn bench_etl_pipeline(c: &mut Criterion) {
     let rt = tokio::runtime::Runtime::new().unwrap();
     let mut group = c.benchmark_group("etl_scaling");

benches/realistic/memory_efficiency.rs

@@ -1,8 +1,8 @@
 //! Memory efficiency benchmark with large data structures
 
 use criterion::{BenchmarkId, Criterion};
-use dagx::{task_fn, DagRunner, TaskHandle};
-
+use dagx::{DagRunner, TaskHandle};
+use dagx_test::task_fn;
 use std::hint::black_box;
 
 pub fn bench_memory_efficiency(c: &mut Criterion) {

benches/realistic/mixed.rs

@@ -1,8 +1,8 @@
 //! Mixed realistic patterns - fan-out, fan-in, and processing
 
 use criterion::Criterion;
-use dagx::{task_fn, DagRunner, TaskHandle};
-
+use dagx::{DagRunner, TaskHandle};
+use dagx_test::task_fn;
 pub fn bench_mixed_patterns(c: &mut Criterion) {
     let rt = tokio::runtime::Runtime::new().unwrap();