test: 完善多份测试用例的类型标注与校验逻辑

1. 为多个测试函数补充pytest.CaptureFixture[str]类型注解
2. 为graphlib类型声明文件补全方法参数类型
3. 为pdftool测试的mock函数添加Any类型标注
4. 新增数据库连接非空校验断言
5. 优化emlmanager测试的字典展开格式与修复decode测试bug
6. 为gittool测试添加命令类型列表校验
7. 为envrs测试添加pyrefly忽略注释

tests/cli/test_gittool.py

@@ -107,6 +107,7 @@ class TestTaskSpecDefinitions:
     def test_kill_tgit_spec(self) -> None:
         """kill_tgit spec should be properly defined."""
         assert gittool.kill_tgit.name == "task_kill"
+        assert isinstance(gittool.kill_tgit.cmd, list)
         assert "taskkill" in gittool.kill_tgit.cmd