实现 MinIO 对象存储图片流水线（可迁移 OSS）

- 新增 S3 兼容 Storage 抽象与 MinIO 实现，compose 启动 MinIO
- 上传接口：校验 → 缩放 → WebP → 主图/缩略图入库
- 消息图片 content 改为对象 URL，拒绝 base64
- 工作台/访客端改为先上传再发消息

server/cmd/main.go

@@ -1,13 +1,16 @@
 package main
 
 import (
+	"context"
 	"log"
+	"time"
 
 	"github.com/gin-gonic/gin"
 	"kefu-sys/server/internal/config"
 	"kefu-sys/server/internal/handler"
 	"kefu-sys/server/internal/middleware"
 	"kefu-sys/server/internal/model"
+	"kefu-sys/server/internal/storage"
 	"kefu-sys/server/internal/ws"
 )
 
@@ -20,6 +23,19 @@ func main() {
 	// 初始化 JWT
 	middleware.InitJWT(cfg.JWT.Secret)
 
+	// 对象存储（MinIO / S3 兼容）
+	store, err := storage.NewS3(cfg.Storage)
+	if err != nil {
+		log.Fatalf("对象存储初始化失败: %v", err)
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	if err := store.EnsureBucket(ctx); err != nil {
+		log.Printf("警告: 确保存储桶失败（可稍后启动 MinIO）: %v", err)
+	} else {
+		log.Printf("对象存储就绪: %s bucket=%s public=%s", cfg.Storage.Endpoint, cfg.Storage.Bucket, cfg.Storage.PublicBase)
+	}
+
 	// 启动 WebSocket Hub
 	go ws.DefaultHub.Run()
 
@@ -32,7 +48,7 @@ func main() {
 	r.Use(func(c *gin.Context) {
 		c.Header("Access-Control-Allow-Origin", "*")
 		c.Header("Access-Control-Allow-Methods", "GET,POST,PUT,DELETE,OPTIONS")
-		c.Header("Access-Control-Allow-Headers", "Content-Type,Authorization")
+		c.Header("Access-Control-Allow-Headers", "Content-Type,Authorization,X-Visitor-Token")
 		if c.Request.Method == "OPTIONS" {
 			c.AbortWithStatus(204)
 			return
@@ -46,7 +62,7 @@ func main() {
 	})
 
 	// 注册路由
-	handler.SetupRoutes(r)
+	handler.SetupRoutes(r, store, cfg.Storage)
 
 	log.Printf("客服云服务启动在 :%s", cfg.Server.Port)
 	if err := r.Run(":" + cfg.Server.Port); err != nil {