fix: remove Bibliothek from left sidebar (was always on right)

- Removed BlockLibrary section from LeftSidebar.tsx
- Removed unused BlockLibrary import
- Removed unused block-related props from LeftSidebar destructuring
- Bibliothek belongs in right sidebar as a tab (already existed there)

frontend/src/components/LeftSidebar.tsx

@@ -1,7 +1,6 @@
 import React from 'react';
 import type { LeftSidebarProps } from '../types/ui.types';
 import { SEATING_TEMPLATES } from '../services/seatingService';
-import BlockLibrary from './BlockLibrary';
 
 interface ToolDef {
   tool: string;
@@ -57,7 +56,7 @@ const sections: Array<{ label: string; tools: ToolDef[] }> = [
   { label: 'Bestuhlung', tools: sectionBestuhlung },
 ];
 
-const LeftSidebar: React.FC<LeftSidebarProps> = ({ activeTool, onToolChange, selectedTemplate, onTemplateSelect, onCollapse, className, collapsed, onToggleCollapse, blocks, onDragBlock, onBlockCategoryChange, onBlockSearch, onRenameBlock, onDuplicateBlock, onDeleteBlock, onSvgImport, onSaveGroupAsBlock }) => {
+const LeftSidebar: React.FC<LeftSidebarProps> = ({ activeTool, onToolChange, selectedTemplate, onTemplateSelect, onCollapse, className, collapsed, onToggleCollapse }) => {
   return (
     <aside className={`leftbar${className ? ' ' + className : ''}${collapsed ? ' leftbar-collapsed' : ''}`} aria-label="Werkzeugpalette">
       <div className="leftbar-header">
@@ -121,21 +120,6 @@ const LeftSidebar: React.FC<LeftSidebarProps> = ({ activeTool, onToolChange, sel
         </div>
       )}
 
-      <div className="tool-section" key="library">
-        <div className="tool-section-label">Bibliothek</div>
-          <BlockLibrary
-            blocks={blocks || []}
-            category="Alle"
-            onCategoryChange={onBlockCategoryChange ?? (() => {})}
-            onSearch={onBlockSearch ?? (() => {})}
-            onDragBlock={onDragBlock ?? (() => {})}
-            onRenameBlock={onRenameBlock}
-            onDuplicateBlock={onDuplicateBlock}
-            onDeleteBlock={onDeleteBlock}
-            onSvgImport={onSvgImport}
-            onSaveGroupAsBlock={onSaveGroupAsBlock}
-          />
-      </div>
 
       <div className="leftbar-footer">
         {onToggleCollapse && (