feat: implement user authentication and permission-based data filtering

Add user login system with role-based access control:
- Admin users see all data and can filter by any manager
- Regular users only see records where ManagerName matches their username

New components:
- BIPUsersDAO: user authentication and management
- SessionManager: singleton session state management
- LoginDialog: modal login UI for app startup
- init_users.sql: initial user setup script

Permission enforcement:
- Material validation tab: hide manager filter for non-admin, force filter by current user
- Material type management: hide filter UI for non-admin, filter at database level
- Window title and status bar display current user info

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

gui/main_window.py

@@ -18,18 +18,21 @@ from gui.settings_tab import SettingsTab
 class MainWindow:
     """主窗口类"""
 
-    def __init__(self, root: tk.Tk):
+    def __init__(self, root: tk.Tk, session_manager):
         """
         初始化主窗口
 
         Args:
             root: Tk 根窗口
+            session_manager: SessionManager 实例，用于用户认证和权限管理
         """
         self.root = root
         self.config = ConfigManager()
+        self.session_manager = session_manager
 
-        # 设置窗口属性
-        self.root.title("ERP 自动化工具 v1.0")
+        # 设置窗口属性（包含用户信息）
+        user_type_display = "管理员" if session_manager.is_admin() else "用户"
+        self.root.title(f"ERP 自动化工具 v1.0 - {session_manager.get_username()} ({user_type_display})")
         self.root.geometry("1000x700")
 
         # 设置最小窗口大小
@@ -72,8 +75,8 @@ class MainWindow:
         self.extraction_tab = DataExtractionTab(self.notebook, self.config)
         self.notebook.add(self.extraction_tab, text="数据提取")
 
-        # 物料校验标签页
-        self.validation_tab = MaterialValidationTab(self.notebook, self.config)
+        # 物料校验标签页（传入 session_manager）
+        self.validation_tab = MaterialValidationTab(self.notebook, self.config, self.session_manager)
         self.notebook.add(self.validation_tab, text="物料校验")
 
         # 数据查询标签页
@@ -97,6 +100,15 @@ class MainWindow:
         )
         status_label.pack(side=tk.LEFT, padx=5)
 
+        # 用户信息显示
+        user_type_display = "管理员" if self.session_manager.is_admin() else "用户"
+        self.user_info_var = tk.StringVar()
+        self.user_info_var.set(f"当前用户: {self.session_manager.get_username()} ({user_type_display})")
+        user_label = ttk.Label(
+            self.status_bar, textvariable=self.user_info_var, anchor=tk.E
+        )
+        user_label.pack(side=tk.RIGHT, padx=5)
+
         # 配置状态指示
         self.config_status = tk.StringVar()
         self.config_status.set("配置已加载")