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_pdftool.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 from pathlib import Path
+from typing import Any
 from unittest.mock import MagicMock, patch
 
 import pytest
@@ -71,7 +72,7 @@ class TestPdfCompress:
             mock_fitz_open.return_value = mock_doc
 
             # Mock save to actually create the file
-            def mock_save(*args, **kwargs):
+            def mock_save(*args: Any, **kwargs: Any):
                 output_file.write_bytes(b"Compressed PDF")
 
             mock_doc.save = mock_save