style: normalize code formatting across the codebase

- Standardize quote style (single to double quotes)
- Improve code formatting consistency
- Apply formatting to utilities, GUI components, and tools
- Update imports and docstrings for consistency

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

gui/progress.py

@@ -17,7 +17,10 @@ class ProgressInfo:
 
     用于在后台任务和 GUI 之间传递进度信息。
     """
-    stage: str  # 阶段标识: 'login', 'query', 'download', 'logout', 'convert', 'complete'
+
+    stage: (
+        str  # 阶段标识: 'login', 'query', 'download', 'logout', 'convert', 'complete'
+    )
     current: int  # 当前进度值
     total: int  # 总量
     message: str  # 显示给用户的消息
@@ -43,12 +46,12 @@ class ProgressCalculator:
 
     # 各阶段在总进度中的占比
     STAGE_WEIGHTS = {
-        'login': 5,      # 登录: 0-5%
-        'query': 5,      # 查询: 5-10%
-        'download': 65,  # 下载: 10-75%
-        'logout': 5,     # 注销: 75-80%
-        'convert': 15,   # 转换: 80-95%
-        'complete': 5,   # 完成: 95-100%
+        "login": 5,  # 登录: 0-5%
+        "query": 5,  # 查询: 5-10%
+        "download": 65,  # 下载: 10-75%
+        "logout": 5,  # 注销: 75-80%
+        "convert": 15,  # 转换: 80-95%
+        "complete": 5,  # 完成: 95-100%
     }
 
     def __init__(self):
@@ -76,7 +79,7 @@ class ProgressCalculator:
         """
         stage = progress.stage
 
-        if stage == 'complete':
+        if stage == "complete":
             return 100
 
         if stage not in self._stage_offsets: