feat: implement user authentication system

- Add SessionManager for managing user sessions (singleton pattern)
- Add BIPUsersDAO for database authentication
- Add LoginDialog component for username/password login
- Add UserSelectionDialog component for admin user selection
- Support silent login by computer name
- Implement main page with navigation to Extractor and Cleaner

Database:
- Table: dbo_BIPUsers
- Fields: UserName, Password, UserType, ComputerNmae

UI Flow:
1. Silent login on startup via computer name
2. Show login dialog if silent login fails
3. Display main page with user info and navigation
4. Support logout and re-login

src/main/ipc/auth-handler.ts

@@ -0,0 +1,223 @@
+/**
+ * IPC handlers for User Authentication
+ *
+ * Provides APIs for the renderer process to:
+ * - Login with username and password
+ * - Silent login by computer name
+ * - Logout
+ * - Get current user info
+ * - Get all users (for admin user selection)
+ * - Switch user (admin only)
+ */
+
+import { ipcMain } from 'electron'
+import { SessionManager } from '../services/user/session-manager'
+import type { UserInfo } from '../types/user.types'
+
+/**
+ * Login request
+ */
+export interface LoginRequest {
+  username: string
+  password: string
+}
+
+/**
+ * Login response
+ */
+export interface LoginResponse {
+  success: boolean
+  userInfo?: UserInfo
+  error?: string
+}
+
+/**
+ * Silent login response
+ */
+export interface SilentLoginResponse {
+  success: boolean
+  userInfo?: UserInfo
+  requiresUserSelection?: boolean // True if admin needs to select a user
+  error?: string
+}
+
+/**
+ * User selection response
+ */
+export interface UserSelectionResponse {
+  success: boolean
+  userInfo?: UserInfo
+  error?: string
+}
+
+/**
+ * Current user response
+ */
+export interface CurrentUserResponse {
+  isAuthenticated: boolean
+  userInfo?: UserInfo
+}
+
+/**
+ * Register IPC handlers for user authentication
+ */
+export function registerAuthHandlers(): void {
+  const sessionManager = SessionManager.getInstance()
+
+  /**
+   * Get computer name
+   */
+  ipcMain.handle('auth:getComputerName', async (): Promise<string> => {
+    const os = await import('os')
+    return os.hostname()
+  })
+
+  /**
+   * Silent login by computer name
+   */
+  ipcMain.handle(
+    'auth:silentLogin',
+    async (): Promise<SilentLoginResponse> => {
+      try {
+        const success = await sessionManager.loginByComputerName()
+        const userInfo = sessionManager.getUserInfo()
+
+        if (success && userInfo) {
+          // Check if admin needs user selection
+          const requiresUserSelection = userInfo.userType === 'Admin'
+
+          return {
+            success: true,
+            userInfo,
+            requiresUserSelection
+          }
+        }
+
+        return {
+          success: false,
+          requiresUserSelection: false
+        }
+      } catch (error) {
+        const message = error instanceof Error ? error.message : 'Unknown error'
+        return {
+          success: false,
+          error: `无感登录失败：${message}`
+        }
+      }
+    }
+  )
+
+  /**
+   * Login with username and password
+   */
+  ipcMain.handle(
+    'auth:login',
+    async (_event, request: LoginRequest): Promise<LoginResponse> => {
+      try {
+        const { username, password } = request
+
+        if (!username || !password) {
+          return {
+            success: false,
+            error: '请输入用户名和密码'
+          }
+        }
+
+        const success = await sessionManager.login(username, password)
+        const userInfo = sessionManager.getUserInfo()
+
+        if (success && userInfo) {
+          return {
+            success: true,
+            userInfo
+          }
+        }
+
+        return {
+          success: false,
+          error: '用户名或密码错误'
+        }
+      } catch (error) {
+        const message = error instanceof Error ? error.message : 'Unknown error'
+        return {
+          success: false,
+          error: `登录失败：${message}`
+        }
+      }
+    }
+  )
+
+  /**
+   * Logout
+   */
+  ipcMain.handle('auth:logout', async (): Promise<void> => {
+    sessionManager.logout()
+  })
+
+  /**
+   * Get current user
+   */
+  ipcMain.handle(
+    'auth:getCurrentUser',
+    async (): Promise<CurrentUserResponse> => {
+      const isAuthenticated = sessionManager.isAuthenticated()
+      const userInfo = sessionManager.getUserInfo()
+
+      return {
+        isAuthenticated,
+        userInfo: userInfo ?? undefined
+      }
+    }
+  )
+
+  /**
+   * Get all users (for admin user selection)
+   */
+  ipcMain.handle(
+    'auth:getAllUsers',
+    async (): Promise<UserInfo[]> => {
+      return await sessionManager.getAllUsers()
+    }
+  )
+
+  /**
+   * Switch user (admin only)
+   */
+  ipcMain.handle(
+    'auth:switchUser',
+    async (_event, userInfo: UserInfo): Promise<UserSelectionResponse> => {
+      try {
+        const success = sessionManager.switchUser(userInfo)
+
+        if (success) {
+          const newUser = sessionManager.getUserInfo()
+          return {
+            success: true,
+            userInfo: newUser ?? undefined
+          }
+        }
+
+        return {
+          success: false,
+          error: '用户切换失败'
+        }
+      } catch (error) {
+        const message = error instanceof Error ? error.message : 'Unknown error'
+        return {
+          success: false,
+          error: `用户切换失败：${message}`
+        }
+      }
+    }
+  )
+
+  /**
+   * Check if current user is admin
+   */
+  ipcMain.handle(
+    'auth:isAdmin',
+    async (): Promise<boolean> => {
+      return sessionManager.isAdmin()
+    }
+  )
+}