feat(socket-proxy): implement Docker socket proxy and related configurations

- Updated Dockerfile and Makefile for socket-proxy build.
- Modified go.mod to include necessary dependencies.
- Updated CI workflows for socket-proxy integration.
- Better module isolation
- Code refactor

agent/pkg/handler/check_health.go

@@ -1,13 +1,13 @@
 package handler
 
 import (
+	"encoding/json"
 	"fmt"
 	"net/http"
 	"net/url"
 	"os"
 	"strings"
 
-	"github.com/yusing/go-proxy/internal/net/gphttp"
 	"github.com/yusing/go-proxy/internal/watcher/health"
 	"github.com/yusing/go-proxy/internal/watcher/health/monitor"
 )
@@ -73,5 +73,7 @@ func CheckHealth(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	gphttp.RespondJSON(w, r, result)
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(result)
 }