优化：工具栏高度对齐+面板统一+远程连接架构+自动恢复预览

- 工具栏：面包屑与右侧组件像素级等高(:deep 34px)、合并重复search handler、统一分隔符样式、删除死代码
- 面板对齐：三面板header统一padding/font-size、文件列表分页固定底部(自定义紧凑)、表头默认隐藏、滚动条统一样式
- 预览区：始终显示空白预览面板、重启自动恢复上次打开文件
- 收藏夹：简化计数显示(共N项)
- 远程连接：ConnectionIndicator自适应UI(无远程显示mini云图标)、ConnectionDialog支持编辑配置、transport抽象层(本地Wails/远程HTTP双模式)、agent后端模块

cmd/agent/main.go

@@ -0,0 +1,105 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"u-desk/internal/agent/config"
+	agentmw "u-desk/internal/agent/middleware"
+	"u-desk/internal/agent/handler"
+	"u-desk/internal/filesystem"
+
+	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v4/middleware"
+)
+
+func main() {
+	cfg, err := config.Load("configs/agent.yaml")
+	if err != nil {
+		log.Fatalf("[FATAL] 加载配置失败: %v", err)
+	}
+
+	fsConfig := filesystem.DefaultConfig()
+	fsSvc, err := filesystem.NewFileSystemService(fsConfig)
+	if err != nil {
+		log.Fatalf("[FATAL] 初始化文件服务失败: %v", err)
+	}
+
+	e := echo.New()
+	e.HideBanner = true
+	e.HidePort = true
+
+	e.Use(middleware.Recover())
+	e.Use(middleware.Logger())
+	e.Use(middleware.CORSWithConfig(middleware.CORSConfig{
+		AllowOrigins: cfg.CORS.AllowedOrigins,
+		AllowMethods: []string{echo.GET, echo.PUT, echo.POST, echo.DELETE, echo.PATCH, echo.OPTIONS},
+		AllowHeaders: []string{echo.HeaderOrigin, echo.HeaderContentType, echo.HeaderAuthorization, echo.HeaderAccept},
+	}))
+	if cfg.Auth.Token != "" {
+		e.Use(agentmw.Auth(cfg.Auth.Token))
+	}
+
+	h := handler.New(fsSvc, cfg)
+
+	api := e.Group("/api/v1")
+	{
+		api.GET("/ping", h.Ping)
+		api.GET("/info", h.Info)
+
+		// 文件操作 — 所有通过 ?path= 参数传递路径
+		api.GET("/fs", h.ListOrStat)           // ?path=xxx [&action=stat]
+		api.GET("/fs/read", h.ReadFile)         // ?path=xxx
+		api.PUT("/fs/write", h.WriteFile)        // ?path=xxx & body={content}
+		api.POST("/fs/create", h.Create)          // ?path=xxx & body={type,name}
+		api.DELETE("/fs/delete", h.Delete)       // ?path=xxx
+		api.PATCH("/fs/rename", h.Rename)        // ?path=xxx & body={new_path}
+		api.POST("/fs/upload", h.Upload)         // ?path=xxx & body={content}
+		api.GET("/fs/detect", h.DetectType)      // ?path=xxx
+
+		sys := api.Group("/system")
+		{
+			sys.GET("/common-paths", h.CommonPaths)
+			sys.GET("/drives", h.Drives)
+		}
+
+		proxy := api.Group("/proxy")
+		{
+			proxy.GET("/localfs/*", h.FileServerProxy)
+			proxy.GET("/html-preview", h.HTMLPreviewProxy)
+		}
+	}
+
+	addr := fmt.Sprintf("%s:%d", cfg.Server.Host, cfg.Server.Port)
+	go func() {
+		log.Printf("[INFO] u-fs-agent 启动于 %s", addr)
+		if err := e.Start(addr); err != nil && err != http.ErrServerClosed {
+			log.Fatalf("[FATAL] HTTP 服务器错误: %v", err)
+		}
+	}()
+
+	go func() {
+		if _, err := filesystem.StartLocalFileServer(); err != nil {
+			log.Printf("[WARN] 文件服务器启动失败（媒体预览不可用）: %v", err)
+		}
+	}()
+
+	quit := make(chan os.Signal, 1)
+	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
+	<-quit
+	log.Println("[INFO] 正在关闭...")
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	filesystem.ShutdownLocalFileServer()
+	e.Shutdown(ctx)
+	fsSvc.Close(ctx)
+	log.Println("[INFO] 已关闭")
+}