fix: clipboard error handling, Escape key support, per-notification read state

frontend/src/components/HelpPanel.tsx

@@ -27,8 +27,12 @@ const quickStart: { step: number; text: string }[] = [
 const HelpPanel: React.FC<HelpPanelProps> = ({ open, onClose }) => {
   if (!open) return null;
 
+  const handleKeyDown = (e: React.KeyboardEvent) => {
+    if (e.key === 'Escape') onClose();
+  };
+
   return (
-    <div className="modal-backdrop" onClick={onClose}>
+    <div className="modal-backdrop" onClick={onClose} onKeyDown={handleKeyDown} tabIndex={-1}>
       <div className="modal-panel help-panel" onClick={(e) => e.stopPropagation()}>
         <div className="modal-header">
           <h2>Hilfe</h2>

frontend/src/components/NotificationPanel.tsx

@@ -6,17 +6,17 @@ interface Notification {
   icon: string;
   title: string;
   timestamp: string;
+  read: boolean;
 }
 
 const initialNotifications: Notification[] = [
-  { id: 'n1', icon: '💾', title: 'Projekt automatisch gespeichert', timestamp: 'vor 2 Min.' },
-  { id: 'n2', icon: '🔄', title: 'Neue Version verfügbar', timestamp: 'vor 15 Min.' },
-  { id: 'n3', icon: '👤', title: 'Benutzer ist beigetreten', timestamp: 'vor 1 Std.' },
+  { id: 'n1', icon: '💾', title: 'Projekt automatisch gespeichert', timestamp: 'vor 2 Min.', read: false },
+  { id: 'n2', icon: '🔄', title: 'Neue Version verfügbar', timestamp: 'vor 15 Min.', read: false },
+  { id: 'n3', icon: '👤', title: 'Benutzer ist beigetreten', timestamp: 'vor 1 Std.', read: false },
 ];
 
 const NotificationPanel: React.FC<NotificationPanelProps> = ({ open, onClose }) => {
   const [notifications, setNotifications] = useState<Notification[]>(initialNotifications);
-  const [allRead, setAllRead] = useState(false);
   const ref = useRef<HTMLDivElement>(null);
 
   useEffect(() => {
@@ -26,8 +26,15 @@ const NotificationPanel: React.FC<NotificationPanelProps> = ({ open, onClose })
         onClose();
       }
     };
+    const handleKeyDown = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') onClose();
+    };
     document.addEventListener('mousedown', handleClickOutside);
-    return () => document.removeEventListener('mousedown', handleClickOutside);
+    document.addEventListener('keydown', handleKeyDown);
+    return () => {
+      document.removeEventListener('mousedown', handleClickOutside);
+      document.removeEventListener('keydown', handleKeyDown);
+    };
   }, [open, onClose]);
 
   if (!open) return null;
@@ -37,7 +44,7 @@ const NotificationPanel: React.FC<NotificationPanelProps> = ({ open, onClose })
   };
 
   const handleMarkAllRead = () => {
-    setAllRead(true);
+    setNotifications((prev) => prev.map((n) => ({ ...n, read: true })));
   };
 
   return (
@@ -53,7 +60,7 @@ const NotificationPanel: React.FC<NotificationPanelProps> = ({ open, onClose })
           <p className="notif-empty">Keine Benachrichtigungen</p>
         ) : (
           notifications.map((n) => (
-            <div key={n.id} className={`notif-item ${allRead ? 'read' : ''}`}>
+            <div key={n.id} className={`notif-item ${n.read ? 'read' : ''}`}>
               <span className="notif-icon">{n.icon}</span>
               <div className="notif-content">
                 <span className="notif-title">{n.title}</span>

frontend/src/components/ShareDialog.tsx

@@ -14,9 +14,15 @@ const ShareDialog: React.FC<ShareDialogProps> = ({ open, onClose, projectName })
     navigator.clipboard.writeText(shareLink).then(() => {
       setCopied(true);
       setTimeout(() => setCopied(false), 2000);
+    }).catch(() => {
+      setCopied(false);
     });
   };
 
+  const handleKeyDown = (e: React.KeyboardEvent) => {
+    if (e.key === 'Escape') onClose();
+  };
+
   const handleInvite = () => {
     if (email.trim()) {
       setInvited(true);
@@ -26,7 +32,7 @@ const ShareDialog: React.FC<ShareDialogProps> = ({ open, onClose, projectName })
   };
 
   return (
-    <div className="modal-backdrop" onClick={onClose}>
+    <div className="modal-backdrop" onClick={onClose} onKeyDown={handleKeyDown} tabIndex={-1}>
       <div className="modal-panel share-dialog" onClick={(e) => e.stopPropagation()}>
         <div className="modal-header">
           <h2>Projekt teilen</h2>