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/pkg/logger/errs.go

@@ -0,0 +1,9 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+// Package logger 提供结构化日志封装
+package logger
+
+const (
+	errCreateLogFileDirFailed = "[Logger] create log file dir err: %w"
+)