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>

init_users.sql

@@ -0,0 +1,23 @@
+-- =============================================
+-- Initial User Setup for [dbo].[BIPUsers] Table
+-- =============================================
+-- This script creates initial users for the ERP Automation Tool
+--
+-- IMPORTANT: Change these passwords before deploying to production!
+-- =============================================
+
+-- Create admin user (can see all data)
+INSERT INTO [dbo].[BIPUsers] (UserName, Password, UserType) VALUES ('admin', 'admin123', 'Admin');
+
+-- Create regular users (replace with actual usernames)
+-- These users will only see records where ManagerName matches their username
+INSERT INTO [dbo].[BIPUsers] (UserName, Password, UserType) VALUES ('user1', 'password1', 'User');
+INSERT INTO [dbo].[BIPUsers] (UserName, Password, UserType) VALUES ('user2', 'password2', 'User');
+
+-- Example: Create users for specific managers
+-- Replace 'ManagerName1', 'ManagerName2' with actual manager names from your data
+-- INSERT INTO [dbo].[BIPUsers] (UserName, Password, UserType) VALUES ('张三', 'password123', 'User');
+-- INSERT INTO [dbo].[BIPUsers] (UserName, Password, UserType) VALUES ('李四', 'password456', 'User');
+
+-- Verify created users
+SELECT * FROM [dbo].[BIPUsers];