refactor(repo): replace legacy openflare-server with Wavelet rename

Delete the old monolithic openflare-server implementation and rename
Wavelet/ to openflare-server/ to complete the migration consolidation.
Update CI workflows, agent Dockerfiles, and deployment docs for the new
layout (frontend/, docker/Dockerfile).

openflare-server/internal/common/errs.go

@@ -0,0 +1,11 @@
+// Copyright 2025 linux.do
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package common
+
+// 通用业务错误消息常量
+const (
+	BannedAccount = "账号已被封禁"
+	UnAuthorized  = "未登录"
+)