refactor(repo): consolidate openflare-server to root and move subprojects to internal/apps

- Merge all files inside openflare-server to the repository root directory.
- Relocate agent, relay, and flared subprojects from internal/ to internal/apps/.
- Combine docker-compose files and update build context paths to root.
- Update GitHub workflows and Dockerfiles to refer to new directories and package names.
- Rewrite Go package imports across all files.
- Resolve database renew test race condition and clean up docs.

internal/cmd/api.go

@@ -0,0 +1,21 @@
+// Copyright 2025 linux.do
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package cmd
+
+import (
+	"github.com/Rain-kl/Wavelet/internal/bootstrap"
+	"github.com/Rain-kl/Wavelet/internal/router"
+	"github.com/spf13/cobra"
+)
+
+var apiCmd = &cobra.Command{
+	Use:   "api",
+	Short: "wavelet API",
+	Run: func(_ *cobra.Command, _ []string) {
+		bootstrap.RegisterAPI()
+		runBootstrap(bootstrap.Options{API: true})
+		router.Serve()
+	},
+}