task(F1-frontend): library export/import buttons in block library tree

frontend/src/components/BlockLibraryTree.tsx

@@ -9,6 +9,8 @@ import {
   createGlobalBlock,
   renameGlobalBlock,
   deleteGlobalBlock,
+  exportLibrary,
+  importLibrary,
 } from '../services/api';
 
 interface BlockLibraryTreeProps {
@@ -38,6 +40,7 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
   } | null>(null);
   const [loading, setLoading] = useState(true);
   const fileInputRef = useRef<HTMLInputElement>(null);
+  const wcadInputRef = useRef<HTMLInputElement>(null);
   const [dragOverFolderId, setDragOverFolderId] = useState<string | null>(null);
 
   const loadData = useCallback(async () => {
@@ -59,6 +62,39 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
     loadData();
   }, [loadData]);
 
+  // ─── Task F1: Library-Paket Export/Import ────────────────
+
+  const handleLibraryExport = useCallback(async () => {
+    try {
+      const pkg = await exportLibrary(token);
+      const blob = new Blob([JSON.stringify(pkg, null, 2)], { type: 'application/json' });
+      const url = URL.createObjectURL(blob);
+      const a = document.createElement('a');
+      a.href = url;
+      a.download = `web-cad-library-${new Date().toISOString().slice(0, 10)}.wcadlib`;
+      a.click();
+      URL.revokeObjectURL(url);
+    } catch (err) {
+      alert(`Library-Export fehlgeschlagen: ${err instanceof Error ? err.message : String(err)}`);
+    }
+  }, [token]);
+
+  const handleWcadFile = useCallback(async (e: React.ChangeEvent<HTMLInputElement>) => {
+    const file = e.target.files?.[0];
+    if (!file) return;
+    try {
+      const text = await file.text();
+      const pkg = JSON.parse(text);
+      const result = await importLibrary(token, pkg);
+      alert(`Bibliothek importiert: ${result.imported_blocks} Blöcke, ${result.imported_folders} Ordner`);
+      await loadData();
+    } catch (err) {
+      alert(`Library-Import fehlgeschlagen: ${err instanceof Error ? err.message : String(err)}`);
+    } finally {
+      e.target.value = '';
+    }
+  }, [token, loadData]);
+
   // Build tree structure from flat lists
   const buildTree = useCallback((): FolderNode[] => {
     const folderMap = new Map<string, FolderNode>();
@@ -366,6 +402,20 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
     <div className="global-lib-tree" onContextMenu={(e) => handleContextMenu(e, 'root', null, null)}>
       <div className="global-lib-header">
         <span className="global-lib-title">🌐 Globale Bibliothek</span>
+        <button
+          className="global-lib-add-btn"
+          title="Bibliothek als .wcadlib exportieren"
+          onClick={() => void handleLibraryExport()}
+        >
+          <svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="7 10 12 17 17 8"/><line x1="12" y1="3" x2="12" y2="15"/></svg>
+        </button>
+        <button
+          className="global-lib-add-btn"
+          title=".wcadlib-Bibliothek importieren"
+          onClick={() => wcadInputRef.current?.click()}
+        >
+          <svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="7 10 12 15 17 10"/><line x1="12" y1="15" x2="12" y2="3"/></svg>
+        </button>
         <button
           className="global-lib-add-btn"
           title="SVG in globale Bibliothek importieren"
@@ -374,6 +424,7 @@ const BlockLibraryTree: React.FC<BlockLibraryTreeProps> = ({ token, onBlockDragS
           <svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="17 8 12 3 7 8"/><line x1="12" y1="3" x2="12" y2="15"/></svg>
         </button>
         <input ref={fileInputRef} type="file" accept=".svg,image/svg+xml" style={{ display: 'none' }} onChange={handleSvgImport} />
+        <input ref={wcadInputRef} type="file" accept=".wcadlib,application/json" style={{ display: 'none' }} onChange={handleWcadFile} />
       </div>
       <div className="tree tree-global" role="tree" aria-label="Globale Block-Bibliothek">
         {tree.map(node => renderFolderNode(node, 0))}

frontend/src/services/api.ts

@@ -812,3 +812,33 @@ export async function deleteGuest(token: string, id: string): Promise<void> {
   });
   if (!res.ok) throw new Error(`Failed to delete guest: ${res.status}`);
 }
+
+// ─── Library Paket Export/Import (Task F1) ─────────────
+export interface WcadlibPackage {
+  format: 'wcadlib';
+  version: number;
+  exported_at?: string;
+  folders: Array<{ id: string; name: string; parent_id: string | null }>;
+  blocks: Array<{ name: string; folder_id: string | null; block_data: string; svg_data: string | null }>;
+}
+
+export async function exportLibrary(token: string): Promise<unknown> {
+  const res = await fetch(`${API_BASE}/api/global-blocks/export`, {
+    headers: authHeaders(token),
+  });
+  if (!res.ok) throw new Error(`Failed to export library: ${res.status}`);
+  return res.json();
+}
+
+export async function importLibrary(token: string, pkg: { format: string; version?: number; folders?: Array<{ id: string; name: string; parent_id: string | null }>; blocks: Array<{ name: string; folder_id: string | null; block_data: string; svg_data: string | null }> }): Promise<{ imported_blocks: number; imported_folders: number }> {
+  const res = await fetch(`${API_BASE}/api/global-blocks/import`, {
+    method: 'POST',
+    headers: authHeaders(token),
+    body: JSON.stringify(pkg),
+  });
+  if (!res.ok) {
+    const err = await res.text();
+    throw new Error(`Failed to import library: ${res.status} ${err}`);
+  }
+  return res.json();
+}