style: format all Python files with Black

Apply Black formatter to the entire codebase for consistent code style.

Co-Authored-By: Claude (glm-5) <noreply@anthropic.com>

gui/login_dialog.py

@@ -1,6 +1,7 @@
 """
 Login Dialog - Modal dialog for user authentication
 """
+
 import socket
 import tkinter as tk
 from tkinter import ttk, messagebox
@@ -62,7 +63,7 @@ class LoginDialog:
         self._create_widgets()
 
         # Bind Enter key to login button
-        self.dialog.bind('<Return>', lambda e: self._on_login())
+        self.dialog.bind("<Return>", lambda e: self._on_login())
 
         # Focus on username entry
         self.username_entry.focus_set()
@@ -74,19 +75,15 @@ class LoginDialog:
         main_frame.pack(fill=tk.BOTH, expand=True)
 
         # Title
-        title_label = ttk.Label(
-            main_frame,
-            text="请登录",
-            font=('', 16, 'bold')
-        )
+        title_label = ttk.Label(main_frame, text="请登录", font=("", 16, "bold"))
         title_label.pack(pady=(0, 10))
 
         # Computer name display
         computer_name_label = ttk.Label(
             main_frame,
             text=f"当前计算机: {socket.gethostname()}",
-            font=('', 9),
-            foreground='gray'
+            font=("", 9),
+            foreground="gray",
         )
         computer_name_label.pack(pady=(0, 15))
 
@@ -112,28 +109,19 @@ class LoginDialog:
 
         # Login button
         login_btn = ttk.Button(
-            button_frame,
-            text="登录",
-            command=self._on_login,
-            width=10
+            button_frame, text="登录", command=self._on_login, width=10
         )
         login_btn.pack(side=tk.LEFT, padx=5)
 
         # Cancel button
         cancel_btn = ttk.Button(
-            button_frame,
-            text="取消",
-            command=self._on_cancel,
-            width=10
+            button_frame, text="取消", command=self._on_cancel, width=10
         )
         cancel_btn.pack(side=tk.LEFT, padx=5)
 
         # Version info
         version_label = ttk.Label(
-            main_frame,
-            text="v1.0",
-            font=('', 8),
-            foreground='gray'
+            main_frame, text="v1.0", font=("", 8), foreground="gray"
         )
         version_label.pack(side=tk.BOTTOM, pady=10)