Add tenant import progress polling

frontend/composables/useAdmin.ts

@@ -54,11 +54,20 @@ export type TenantImportResult = {
   tenantId: number
   tables: { table: string; rows: number }[]
   files: { restored: number; skipped: number }
+  importId?: string
+  exportId?: string
+  status?: string
+  filename?: string
+  filesDone?: number
+  filesTotal?: number
+  error?: string | null
 }
 
 export type TenantExportJob = {
   exportId: string
+  importId?: string
   tenantId?: number
+  operation?: "export" | "import" | string
   status: "queued" | "running" | "ready" | "failed" | string
   filename: string
   fileSize?: number | null