task(E6-frontend): guest panel with ribbon entry and api client

frontend/src/App.tsx

@@ -19,6 +19,7 @@ import MobileDrawers from './components/MobileDrawers';
 import BackgroundImport from './components/BackgroundImport';
 import HistoryPanel from './components/HistoryPanel';
 import V2HistoryPanel from './components/V2HistoryPanel';
+import GuestPanel from './components/GuestPanel';
 import { V2_TOOLS_ENABLED } from './kernel/featureFlags';
 import SettingsModal from './components/SettingsModal';
 import InlineTextEditor from './components/InlineTextEditor';
@@ -176,6 +177,7 @@ const CADEditor: React.FC<CADEditorProps> = ({ projectId, token, onNavigateBack
 
   // History panel
   const [historyPanelOpen, setHistoryPanelOpen] = useState(false);
+  const [guestPanelOpen, setGuestPanelOpen] = useState(false);
 
   // Export format selector (cross-browser replacement for nwsave)
   const [exportFormatOpen, setExportFormatOpen] = useState(false);
@@ -1148,6 +1150,7 @@ const CADEditor: React.FC<CADEditorProps> = ({ projectId, token, onNavigateBack
     // ─── Tools actions ───
     if (action === 'measure') { setActiveTool('dimension'); setCommandHistory((prev) => [...prev, { prefix: '·', text: 'Messwerkzeug aktiv', type: 'info' }]); return; }
     if (action === 'history') { setHistoryPanelOpen((prev) => !prev); return; }
+    if (action === 'guests') { setGuestPanelOpen((prev) => !prev); return; }
 
     // ─── V2 tools (Task A4.13): 'v2tool:<id>' → aktives Tool umschalten. Der
     // bestehende CanvasArea-Sync aus A4.1 routet es an den Dispatcher (Flag aktiv).
@@ -1762,6 +1765,15 @@ const CADEditor: React.FC<CADEditorProps> = ({ projectId, token, onNavigateBack
           onClose={() => setHistoryPanelOpen(false)}
         />
       ))}
+      {guestPanelOpen && drawingId && (
+        <div className="guest-panel-overlay" style={{ position: 'fixed', top: 60, right: 12, width: 300, maxHeight: '70vh', background: 'var(--bg-secondary, #1e1e2e)', color: 'var(--fg-primary, #e0e0e0)', border: '1px solid rgba(128,128,128,0.3)', borderRadius: 8, boxShadow: '0 4px 16px rgba(0,0,0,0.4)', zIndex: 1000, display: 'flex', flexDirection: 'column' }}>
+          <GuestPanel
+            token={token}
+            drawingId={drawingId}
+            onClose={() => setGuestPanelOpen(false)}
+          />
+        </div>
+      )}
       {exportFormatOpen && (
         <div className="export-format-overlay" onClick={() => setExportFormatOpen(false)}>
           <div className="export-format-modal" onClick={(e) => e.stopPropagation()}>