fix: 安装完成后清除旧的token和user数据

- 修复安装完成后点击前往登录时，旧的token导致直接跳转到后台的问题
- 安装完成后清除localStorage中的token和user数据
- 移除调试日志

backend/pkg/jwt/jwt.go

@@ -2,7 +2,6 @@ package jwt
 
 import (
 	"errors"
-	"log"
 	"time"
 	"verification-platform-backend/internal/config"
 
@@ -24,9 +23,6 @@ func GenerateToken(userID uint, username, role string) (string, error) {
 		expireHours = 24
 	}
 
-	jwtSecret := config.GetString("app.jwt_secret")
-	log.Printf("[JWT] GenerateToken using jwt_secret: %s (length: %d)", jwtSecret, len(jwtSecret))
-
 	expiresAt := time.Now().Add(time.Hour * time.Duration(expireHours))
 
 	claims := Claims{
@@ -42,20 +38,16 @@ func GenerateToken(userID uint, username, role string) (string, error) {
 	}
 
 	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
-	return token.SignedString([]byte(jwtSecret))
+	return token.SignedString([]byte(config.GetString("app.jwt_secret")))
 }
 
 // ParseToken 解析JWT令牌
 func ParseToken(tokenString string) (*Claims, error) {
-	jwtSecret := config.GetString("app.jwt_secret")
-	log.Printf("[JWT] ParseToken using jwt_secret: %s (length: %d)", jwtSecret, len(jwtSecret))
-
 	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
-		return []byte(jwtSecret), nil
+		return []byte(config.GetString("app.jwt_secret")), nil
 	})
 
 	if err != nil {
-		log.Printf("[JWT] ParseToken error: %v", err)
 		return nil, err
 	}