fix(安全): 修复依赖漏洞并强化安全扫描

主要改动：
- 固定 Go 1.25.5 与 CI 校验并更新扫描流程
- 升级 quic-go、x/crypto、req 等依赖并通过 govulncheck
- 强化 JWT 校验、TLS 配置与 xlsx 动态加载
- 新增审计豁免清单与校验脚本

backend/internal/repository/proxy_probe_service.go

@@ -24,7 +24,7 @@ func NewProxyExitInfoProber(cfg *config.Config) service.ProxyExitInfoProber {
 		validateResolvedIP = cfg.Security.URLAllowlist.Enabled
 	}
 	if insecure {
-		log.Printf("[ProxyProbe] Warning: TLS verification is disabled for proxy probing.")
+		log.Printf("[ProxyProbe] Warning: insecure_skip_verify is not allowed and will cause probe failure.")
 	}
 	return &proxyProbeService{
 		ipInfoURL:          defaultIPInfoURL,