refactor: 重构CliRunner，新增cmd工厂函数优化任务定义

1. 新增cmd工厂函数，简化TaskSpec创建并自动推导名称
2. 重构CliRunner，将graphs参数替换为tasks+aliases，支持扁平任务注册与别名映射
3. 替换所有cli工具中的旧版任务定义方式，使用新API简化代码
4. 补充对应测试用例，适配新的运行器API

tests/test_task.py

@@ -14,6 +14,7 @@ from pyflowx.task import (
     TaskSpec,
     TaskStatus,
     _env_and_cwd,
+    cmd,
     task_template,
 )
 
@@ -78,6 +79,41 @@ def test_retry_policy_negative_jitter_rejected() -> None:
         RetryPolicy(jitter=-1)
 
 
+# ---------------------------------------------------------------------- #
+# cmd() 工厂
+# ---------------------------------------------------------------------- #
+def test_cmd_factory_default_name_from_two_elements() -> None:
+    """cmd() 默认 name = '_'.join(command[:2])."""
+    spec = cmd(["uv", "build"])
+    assert spec.name == "uv_build"
+    assert spec.cmd == ["uv", "build"]
+
+
+def test_cmd_factory_default_name_single_element() -> None:
+    """cmd() 单元素命令 name = command[0]."""
+    spec = cmd(["ls"])
+    assert spec.name == "ls"
+
+
+def test_cmd_factory_explicit_name() -> None:
+    """cmd() 显式 name 覆盖默认推导."""
+    spec = cmd(["ruff", "check", "--fix"], name="lint")
+    assert spec.name == "lint"
+
+
+def test_cmd_factory_passes_depends_on() -> None:
+    """cmd() depends_on 透传给 TaskSpec."""
+    spec = cmd(["echo", "b"], name="b", depends_on=("a",))
+    assert spec.depends_on == ("a",)
+
+
+def test_cmd_factory_passes_extra_kwargs() -> None:
+    """cmd() 其余 kwargs 透传给 TaskSpec."""
+    spec = cmd(["echo", "x"], name="x", timeout=10.0, tags=("t1",))
+    assert spec.timeout == 10.0
+    assert spec.tags == ("t1",)
+
+
 def test_retry_policy_retries_property() -> None:
     policy = RetryPolicy(max_attempts=3)
     assert policy.retries == 2