fix: mobile sidebar slide-in overlay with hamburger and panel toggle buttons

- LeftSidebar/RightSidebar: added className prop for 'open' class
- Topbar: wired hamburger onClick + added mobile-drawer-toggle button for right panel
- App.tsx: added SettingsModal import/state/render, passed className props to sidebars
- styles.css: mobile sidebars now fixed slide-in overlays (translateX) instead of display:none
- ui.types.ts: added className to RightSidebarProps, onOpenLeftDrawer/onOpenRightDrawer to TopbarProps
- Tested at 390px viewport: both sidebars slide in correctly, transform verified via DOM

frontend/src/components/RightSidebar.tsx

@@ -14,6 +14,7 @@ const tabs: Array<{ id: RightPanel; label: string; svg: React.ReactNode; badge?:
 
 const RightSidebar: React.FC<RightSidebarProps> = ({
   activePanel, onPanelChange, selectedElement, layers, blocks,
+  className,
   activeLayerId, onSelectLayer, onAddLayer, onToggleLayer,
   onDeleteLayer, onRenameLayer, onDuplicateLayer, onToggleLock,
   onReorder, onAddSubLayer,
@@ -24,7 +25,7 @@ const RightSidebar: React.FC<RightSidebarProps> = ({
   kiMessages, kiSuggestions, onKISend, onKISuggestionClick, kiLoading, onUpdateElement,
 }) => {
   return (
-    <aside className="rightbar" aria-label="Eigenschaften-Panels">
+    <aside className={`rightbar${className ? ' ' + className : ''}`} aria-label="Eigenschaften-Panels">
       <div className="rightbar-tabs" role="tablist">
         {tabs.map((tab) => (
           <button