Improve disk UI and build performance

internal/api/handlers_disk.go

@@ -3,6 +3,7 @@ package api
 import (
 	"encoding/json"
 	"net/http"
+	"time"
 
 	"jukebox_maker/internal/disk"
 )
@@ -14,6 +15,7 @@ func (s *Server) handleDiskStatus(w http.ResponseWriter, r *http.Request) {
 		TotalBytes   int64          `json:"total_bytes"`
 		FreeBytes    int64          `json:"free_bytes"`
 		MountPath    string         `json:"mount_path"`
+		LastCopiedAt string         `json:"last_copied_at,omitempty"`
 		ActiveTaskID string         `json:"active_task_id,omitempty"`
 	}
 
@@ -28,6 +30,9 @@ func (s *Server) handleDiskStatus(w http.ResponseWriter, r *http.Request) {
 			MountPath:  info.MountPath,
 		}
 		if info.DiskID != "" {
+			if lastCopiedAt, ok, err := s.deps.Copier.LastCopiedAt(info.DiskID); err == nil && ok {
+				item.LastCopiedAt = lastCopiedAt.Format(time.RFC3339)
+			}
 			if t, ok := s.deps.Tasks.ActiveTaskByDisk(info.DiskID); ok {
 				item.ActiveTaskID = t.ID
 			}