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/internal/handler/router.go

@@ -2,10 +2,12 @@ package handler
 
 import (
 	"github.com/gin-gonic/gin"
+	"kefu-sys/server/internal/config"
 	"kefu-sys/server/internal/middleware"
+	"kefu-sys/server/internal/storage"
 )
 
-func SetupRoutes(r *gin.Engine) {
+func SetupRoutes(r *gin.Engine, store storage.ObjectStorage, storageCfg config.StorageConfig) {
 	auth := NewAuthHandler()
 	session := NewSessionHandler()
 	customer := NewCustomerHandler()
@@ -16,6 +18,9 @@ func SetupRoutes(r *gin.Engine) {
 	settings := NewSettingsHandler()
 	ws := NewWsHandler()
 	widget := NewWidgetHandler()
+	upload := NewUploadHandler(store, storageCfg)
+
+	SetImagePublicBase(storageCfg.PublicBase)
 
 	api := r.Group("/api")
 
@@ -31,6 +36,7 @@ func SetupRoutes(r *gin.Engine) {
 	widgetApi.GET("/messages", widget.GetMessages)
 	widgetApi.GET("/ws", widget.Connect)
 	widgetApi.POST("/rating", widget.SubmitRating)
+	widgetApi.POST("/upload", upload.WidgetUploadImage)
 
 	// 需要认证的接口
 	authRequired := api.Group("")
@@ -39,6 +45,9 @@ func SetupRoutes(r *gin.Engine) {
 		// WebSocket
 		authRequired.GET("/ws", ws.Connect)
 
+		// 上传
+		authRequired.POST("/uploads", upload.UploadImage)
+
 		// 会话管理
 		authRequired.GET("/agents/available", session.ListAvailableAgents)
 		sessions := authRequired.Group("/sessions")