add toast notification system with success, error, and info variants

src/components/import-export/ImportExportButtons.tsx

@@ -9,6 +9,7 @@ import {
 } from "@/components/ui/dropdown-menu";
 import { useAppStore } from "@/stores/app-store";
 import { useBoardStore } from "@/stores/board-store";
+import { useToastStore } from "@/stores/toast-store";
 import { saveBoard } from "@/lib/storage";
 import {
   exportBoardAsJson,
@@ -31,6 +32,7 @@ function downloadBlob(content: string, filename: string, mimeType: string) {
 
 export function ImportExportButtons() {
   const fileInputRef = useRef<HTMLInputElement>(null);
+  const addToast = useToastStore((s) => s.addToast);
   const board = useBoardStore((s) => s.board);
   const refreshBoards = useAppStore((s) => s.refreshBoards);
   const setView = useAppStore((s) => s.setView);
@@ -42,6 +44,7 @@ export function ImportExportButtons() {
     const json = exportBoardAsJson(board);
     const safeName = board.title.replace(/[^a-zA-Z0-9-_]/g, "_");
     downloadBlob(json, `${safeName}.json`, "application/json");
+    addToast("Board exported as JSON", "success");
   }
 
   function handleExportCsv() {
@@ -49,6 +52,7 @@ export function ImportExportButtons() {
     const csv = exportBoardAsCsv(board);
     const safeName = board.title.replace(/[^a-zA-Z0-9-_]/g, "_");
     downloadBlob(csv, `${safeName}.csv`, "text/csv");
+    addToast("Board exported as CSV", "success");
   }
 
   function handleImportClick() {
@@ -77,9 +81,10 @@ export function ImportExportButtons() {
       await openBoard(imported.id);
       setView({ type: "board", boardId: imported.id });
       addRecentBoard(imported.id);
+      addToast("Board imported successfully", "success");
     } catch (err) {
       console.error("Import failed:", err);
-      // Could show a toast here in the future
+      addToast("Import failed - check file format", "error");
     }
 
     // Reset the input so the same file can be re-imported