refactor(internal): 优化 OSS 预签名 URL 缓存刷新任务和英雄数据缓存逻辑

- 注释掉 OSS预签名 URL 缓存刷新任务的定时执行代码
- 在 hero/hero.go 中增加对 Redis缓存和英雄数据集的非空校验
- 修改 OSS预签名 URL 生成逻辑，自动替换为 CDN 域名

internal/cmd/cmd.go

@@ -7,12 +7,13 @@ import (
 	"epic/internal/logic/i18n"
 	"epic/internal/service"
 	"epic/internal/util"
-	"github.com/gogf/gf/v2/frame/g"
-	"github.com/gogf/gf/v2/net/ghttp"
-	"github.com/gogf/gf/v2/os/gcmd"
 	"os"
 	"os/signal"
 	"syscall"
+
+	"github.com/gogf/gf/v2/frame/g"
+	"github.com/gogf/gf/v2/net/ghttp"
+	"github.com/gogf/gf/v2/os/gcmd"
 )
 
 func CORS(r *ghttp.Request) {