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/apps/openflare/relay/middleware.go

@@ -0,0 +1,49 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package relay
+
+import (
+	"context"
+	"errors"
+	"strings"
+
+	"github.com/Rain-kl/Wavelet/internal/common/response"
+	"github.com/Rain-kl/Wavelet/internal/model"
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+)
+
+const ctxRelayNodeKey = "relay_node"
+
+// RelayAuth authenticates relay requests using X-Agent-Token and verifies tunnel_relay type.
+func RelayAuth() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		token := strings.TrimSpace(c.GetHeader("X-Agent-Token"))
+		node, err := authenticateAccessToken(c.Request.Context(), token)
+		if err != nil {
+			response.AbortUnauthorized(c, errAgentTokenInvalid)
+			return
+		}
+		if node.NodeType != "tunnel_relay" {
+			response.AbortForbidden(c, errRelayNodeTypeMismatch)
+			return
+		}
+		c.Set(ctxRelayNodeKey, node)
+		c.Next()
+	}
+}
+
+func authenticateAccessToken(ctx context.Context, token string) (*model.OpenFlareNode, error) {
+	if token == "" {
+		return nil, errors.New("missing agent token")
+	}
+	node, err := model.GetOpenFlareNodeByAccessToken(ctx, token)
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, errors.New("invalid agent token")
+		}
+		return nil, err
+	}
+	return node, nil
+}