feat: implement QR code scan login system with admin control

- Add scan login service with Redis-based token management
- Add scan login API routes for token generation and validation
- Add QRCodeLogin component for PC-side QR code display
- Add EntryQRCode component for mass login scenarios
- Add ScanLoginView for mobile-side login form
- Add localStorage persistence for user identity
- Add logout functionality to mobile client
- Add auto-redirect for logged-in users
- Add admin console control for QR code display on big screen
- Add socket event forwarding from admin to screen display

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

packages/shared/src/constants/events.ts

@@ -34,6 +34,15 @@ export const SOCKET_EVENTS = {
   ADMIN_EMERGENCY_RESET: 'admin:emergency_reset',
   ADMIN_STATE_SYNC: 'admin:state_sync',
   ADMIN_MUSIC_CONTROL: 'admin:music_control',
+
+  // Scan login events
+  SCAN_SUBSCRIBE: 'scan:subscribe',
+  SCAN_UNSUBSCRIBE: 'scan:unsubscribe',
+  SCAN_STATUS_UPDATE: 'scan:status_update',
+
+  // QR code display control events
+  DISPLAY_SHOW_ENTRY_QR: 'display:show_entry_qr',
+  DISPLAY_HIDE_QR: 'display:hide_qr',
 } as const;
 
 export const SOCKET_ROOMS = {

packages/shared/src/types/index.ts

@@ -3,3 +3,4 @@ export * from './socket.types';
 export * from './vote.types';
 export * from './draw.types';
 export * from './admin.types';
+export * from './scan-login.types';

packages/shared/src/types/scan-login.types.ts

@@ -0,0 +1,66 @@
+// Scan login types
+
+export type ScanLoginStatus = 'pending' | 'scanned' | 'confirmed' | 'expired';
+
+export interface ScanTokenData {
+  scanToken: string;
+  pcSocketId: string;
+  status: ScanLoginStatus;
+  createdAt: number;
+  expiresAt: number;
+  userInfo?: {
+    userId: string;
+    userName: string;
+    department: string;
+  };
+}
+
+export interface GenerateScanTokenResponse {
+  success: boolean;
+  data?: {
+    scanToken: string;
+    qrCodeUrl: string;
+    expiresAt: number;
+  };
+  error?: string;
+}
+
+export interface ValidateTokenResponse {
+  success: boolean;
+  data?: {
+    valid: boolean;
+    status: ScanLoginStatus;
+    expiresAt: number;
+  };
+  error?: string;
+}
+
+export interface ScanConfirmPayload {
+  scanToken: string;
+  userName: string;
+  department: string;
+}
+
+export interface ScanConfirmResponse {
+  success: boolean;
+  data?: {
+    sessionToken: string;
+    userId: string;
+  };
+  error?: string;
+}
+
+export interface ScanStatusUpdatePayload {
+  scanToken: string;
+  status: ScanLoginStatus;
+  userInfo?: {
+    userId: string;
+    userName: string;
+    department: string;
+    sessionToken: string;
+  };
+}
+
+export interface ScanSubscribePayload {
+  scanToken: string;
+}