refactor: 新增base.Repo与base.App，重构repo与app层代码

server/internal/sys/api/captcha.go

@@ -1,12 +1,14 @@
 package api
 
 import (
+	"mayfly-go/pkg/biz"
 	"mayfly-go/pkg/captcha"
 	"mayfly-go/pkg/req"
 	"mayfly-go/pkg/utils/collx"
 )
 
 func GenerateCaptcha(rc *req.Ctx) {
-	id, image := captcha.Generate()
+	id, image, err := captcha.Generate()
+	biz.ErrIsNilAppendErr(err, "获取验证码错误: %s")
 	rc.ResData = collx.M{"base64Captcha": image, "cid": id}
 }