refactor: 全面迁移至 Python 3.9+ 原生泛型类型语法

- 将所有 `Optional[T]` 替换为 `T | None`
- 将所有 `List[T]`/`Dict[K, V]`/`Tuple[Ts, ...]` 替换为对应原生泛型
- 调整类型导入，移除冗余的 typing 导入项
- 更新项目依赖，添加 typing-extensions 兼容旧版本 Python
- 重构部分函数签名与内部实现以匹配新类型语法

tests/test_task_edge_cases.py

@@ -0,0 +1,156 @@
+"""Tests for task module edge cases."""
+
+import sys
+import tempfile
+
+import pytest
+
+import pyflowx as px
+from pyflowx.task import TaskSpec
+
+# 跨平台的 echo 命令
+if sys.platform == "win32":
+    ECHO_CMD = ["cmd", "/c", "echo"]
+else:
+    ECHO_CMD = ["echo"]
+
+
+def test_taskspec_wrap_cmd_with_list():
+    """Test TaskSpec._wrap_cmd with command list."""
+    spec = TaskSpec("test", cmd=[*ECHO_CMD, "hello"])
+    wrapped_fn = spec.effective_fn
+    assert wrapped_fn is not None
+    assert wrapped_fn.__name__ == "test"
+
+
+def test_taskspec_wrap_cmd_with_string():
+    """Test TaskSpec._wrap_cmd with command string."""
+    if sys.platform == "win32":
+        cmd_str = "cmd /c echo hello"
+    else:
+        cmd_str = "echo hello"
+    spec = TaskSpec("test", cmd=cmd_str)
+    wrapped_fn = spec.effective_fn
+    assert wrapped_fn is not None
+    assert wrapped_fn.__name__ == "test"
+
+
+def test_taskspec_wrap_cmd_with_timeout():
+    """Test TaskSpec._wrap_cmd with timeout."""
+    spec = TaskSpec("test", cmd=[*ECHO_CMD, "hello"], timeout=0.1)
+    wrapped_fn = spec.effective_fn
+
+    # Should not raise timeout error for quick command
+    result = wrapped_fn()
+    assert result is None
+
+
+def test_taskspec_wrap_cmd_with_cwd():
+    """Test TaskSpec._wrap_cmd with working directory."""
+    with tempfile.TemporaryDirectory() as tmpdir:
+        spec = TaskSpec("test", cmd=[*ECHO_CMD, "hello"], cwd=tmpdir)
+        wrapped_fn = spec.effective_fn
+        result = wrapped_fn()
+        assert result is None
+
+
+def test_taskspec_wrap_cmd_verbose():
+    """Test TaskSpec._wrap_cmd with verbose=True."""
+    spec = TaskSpec("test", cmd=[*ECHO_CMD, "hello"], verbose=True)
+    wrapped_fn = spec.effective_fn
+
+    # Should print verbose output
+    result = wrapped_fn()
+    assert result is None
+
+
+def test_taskspec_wrap_cmd_error():
+    """Test TaskSpec._wrap_cmd handles command error."""
+    spec = TaskSpec("test", cmd=["python", "-c", "import sys; sys.exit(1)"])
+    wrapped_fn = spec.effective_fn
+
+    with pytest.raises(RuntimeError, match="命令执行失败"):
+        wrapped_fn()
+
+
+def test_taskspec_wrap_cmd_file_not_found():
+    """Test TaskSpec._wrap_cmd handles file not found."""
+    spec = TaskSpec("test", cmd=["nonexistent_command"])
+    wrapped_fn = spec.effective_fn
+
+    with pytest.raises(RuntimeError, match="命令未找到"):
+        wrapped_fn()
+
+
+def test_taskspec_wrap_cmd_shell_file_not_found():
+    """Test TaskSpec._wrap_cmd handles shell command file not found."""
+    spec = TaskSpec("test", cmd="nonexistent_shell_command")
+    wrapped_fn = spec.effective_fn
+
+    # Shell commands don't raise FileNotFoundError
+    # They just return non-zero exit code
+    with pytest.raises(RuntimeError):
+        wrapped_fn()
+
+
+def test_taskspec_no_fn_no_cmd():
+    """Test TaskSpec raises error when no fn or cmd."""
+    with pytest.raises(ValueError, match="必须提供 fn 或 cmd 参数"):
+        TaskSpec("test")
+
+
+def test_taskspec_cmd_overrides_fn():
+    """Test TaskSpec cmd overrides fn."""
+
+    def my_fn():
+        return "fn_result"
+
+    spec = TaskSpec("test", fn=my_fn, cmd=[*ECHO_CMD, "hello"])
+    wrapped_fn = spec.effective_fn
+
+    # cmd should override fn
+    assert wrapped_fn.__name__ == "test"
+
+
+def test_taskspec_conditions_check():
+    """Test TaskSpec.should_execute with conditions."""
+    spec = px.TaskSpec(
+        "test",
+        fn=lambda: "result",
+        conditions=(lambda: True,),
+    )
+
+    assert spec.should_execute() is True
+
+
+def test_taskspec_conditions_false():
+    """Test TaskSpec.should_execute with false conditions."""
+    spec = px.TaskSpec(
+        "test",
+        fn=lambda: "result",
+        conditions=(lambda: False,),
+    )
+
+    assert spec.should_execute() is False
+
+
+def test_taskspec_conditions_multiple():
+    """Test TaskSpec.should_execute with multiple conditions."""
+    spec = px.TaskSpec(
+        "test",
+        fn=lambda: "result",
+        conditions=(lambda: True, lambda: True, lambda: True),
+    )
+
+    assert spec.should_execute() is True
+
+
+def test_taskspec_conditions_multiple_one_false():
+    """Test TaskSpec.should_execute with one false condition."""
+    spec = px.TaskSpec(
+        "test",
+        fn=lambda: "result",
+        conditions=(lambda: True, lambda: False, lambda: True),
+    )
+
+    assert spec.should_execute() is False