Phase 4: KI-UI-Steuerung — AI agent UI control via WebSocket

- New ai_ui_control plugin: WS endpoint /ws/ai-ui-control, REST API (POST /command, GET /command/{id}/status, GET /online-users)
- UI-Command-Protocol: 6 command types (navigate, filter, open_contact, modal, tab, settings) with Pydantic schemas
- WebSocket manager: per-user connections, command delivery, feedback storage, stale cleanup
- Frontend useAIUIControl hook: WS client with auto-reconnect, command dispatch, feedback sending
- aiUIControlStore: Zustand store for command state, active modal/tab, pending filter/settings
- AIUIControlIndicator: visual KI indication (Bot icon, toast, pulse animation)
- ContactDetail integration: syncs activeTab and personModalOpen from AI control store
- AppShell integration: useAIUIControl hook + AIUIControlIndicator
- i18n keys for DE/EN
- 18 Vitest tests: command protocol, store actions, feedback, visual indication
- TSC: 0 new errors (only 2 pre-existing Dms.tsx errors)

frontend/src/components/ai-ui-control/AIUIControlIndicator.tsx

@@ -0,0 +1,86 @@
+/**
+ * AIUIControlIndicator — Visual indication when AI is controlling the UI.
+ *
+ * Task 4.11: Visuelle KI-Indikation
+ * When AI executes an action: highlight effect + toast "KI führt Aktion aus...".
+ * User sees that AI is acting.
+ */
+
+import React, { useEffect } from 'react';
+import { Bot, X } from 'lucide-react';
+import { useAIUIControlStore } from '@/store/aiUIControlStore';
+import { useUIStore } from '@/store/uiStore';
+import { useTranslation } from 'react-i18next';
+
+export function AIUIControlIndicator() {
+  const { t } = useTranslation();
+  const aiActive = useAIUIControlStore((s) => s.aiActive);
+  const activeCommand = useAIUIControlStore((s) => s.activeCommand);
+  const clearPending = useAIUIControlStore((s) => s.clearPending);
+  const addToast = useUIStore((s) => s.addToast);
+
+  // Show toast when a new command starts
+  useEffect(() => {
+    if (aiActive && activeCommand) {
+      const desc = activeCommand.description || t(`ai.uiControl.${actionToKey(activeCommand.action)}`, getCommandFallback(activeCommand.action));
+      addToast({
+        type: 'info',
+        message: `${t('ai.uiControl.executing', 'KI führt Aktion aus')}: ${desc}`,
+        duration: 4000,
+      });
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [aiActive, activeCommand?.command_id]);
+
+  if (!aiActive) return null;
+
+  return (
+    <div
+      className="fixed top-4 right-4 z-50 flex items-center gap-2 rounded-lg border border-primary-300 bg-primary-50 px-4 py-2 shadow-lg animate-pulse"
+      data-testid="ai-ui-control-indicator"
+      role="status"
+      aria-label={t('ai.uiControl.active', 'KI steuert die UI')}
+    >
+      <Bot className="h-5 w-5 text-primary-600 animate-pulse" aria-hidden="true" />
+      <span className="text-sm font-medium text-primary-700">
+        {t('ai.uiControl.active', 'KI steuert die UI')}
+      </span>
+      {activeCommand?.description && (
+        <span className="text-xs text-primary-500">
+          — {activeCommand.description}
+        </span>
+      )}
+      <button
+        onClick={() => clearPending()}
+        className="ml-2 text-primary-400 hover:text-primary-600"
+        aria-label={t('common.dismiss', 'Schließen')}
+      >
+        <X className="h-4 w-4" />
+      </button>
+    </div>
+  );
+}
+
+function actionToKey(action: string): string {
+  const keyMap: Record<string, string> = {
+    navigate: 'navigate',
+    filter: 'filter',
+    open_contact: 'openContact',
+    modal: 'modal',
+    tab: 'tab',
+    settings: 'settings',
+  };
+  return keyMap[action] || action;
+}
+
+function getCommandFallback(action: string): string {
+  const fallbacks: Record<string, string> = {
+    navigate: 'Navigation',
+    filter: 'Filter setzen',
+    open_contact: 'Kontakt öffnen',
+    modal: 'Dialog öffnen',
+    tab: 'Tab wechseln',
+    settings: 'Einstellungen ändern',
+  };
+  return fallbacks[action] || action;
+}

frontend/src/components/contacts/ContactDetail.tsx

@@ -1,4 +1,4 @@
-import React, { useState } from 'react';
+import React, { useState, useEffect } from 'react';
 import { useTranslation } from 'react-i18next';
 import { Button } from '@/components/ui/Button';
 import { Badge } from '@/components/ui/Badge';
@@ -11,6 +11,7 @@ import { Loader2 } from 'lucide-react';
 import * as LucideIcons from 'lucide-react';
 import { HistoryViewer } from '@/components/HistoryViewer';
 import { usePluginStore } from '@/store/pluginStore';
+import { useAIUIControlStore } from '@/store/aiUIControlStore';
 import { PluginPage } from '@/components/plugins/PluginLoader';
 import { useAuthStore } from '@/store/authStore';
 import {
@@ -155,6 +156,25 @@ export function ContactDetail({ contact, loading, onEdit, onDeleted }: ContactDe
   const [editingPerson, setEditingPerson] = useState<ContactPerson | null>(null);
   const [activeTab, setActiveTab] = useState('details');
   const pluginTabs = usePluginStore(s => s.getDetailTabsForEntity('contact'));
+  const aiActiveTab = useAIUIControlStore(s => s.activeTab);
+  const aiActiveModal = useAIUIControlStore(s => s.activeModal);
+
+  // Sync tab from AI UI Control (Phase 4.8)
+  useEffect(() => {
+    if (aiActiveTab) {
+      setActiveTab(aiActiveTab);
+    }
+  }, [aiActiveTab]);
+
+  // Sync modal from AI UI Control (Phase 4.7)
+  useEffect(() => {
+    if (aiActiveModal === 'edit' || aiActiveModal === 'create') {
+      setEditingPerson(null);
+      setPersonModalOpen(true);
+    } else if (aiActiveModal === 'close') {
+      setPersonModalOpen(false);
+    }
+  }, [aiActiveModal]);
   const user = useAuthStore(s => s.user);
 
   if (loading) {

frontend/src/components/layout/AppShell.tsx

@@ -6,7 +6,9 @@ import { PluginToolbar } from './PluginToolbar';
 import { MessageSidebar } from './MessageSidebar';
 import { ToastContainer } from '@/components/ui/Toast';
 import { useAIContext } from '@/hooks/useAIContext';
+import { useAIUIControl } from '@/hooks/useAIUIControl';
 import { PluginRegistry } from '@/components/plugins/PluginRegistry';
+import { AIUIControlIndicator } from '@/components/ai-ui-control/AIUIControlIndicator';
 
 export function AppShell() {
   const location = useLocation();
@@ -14,6 +16,9 @@ export function AppShell() {
   // Track context for AI Proactive suggestions
   useAIContext();
 
+  // AI UI Control — WebSocket-based UI control from AI agents (Phase 4)
+  useAIUIControl();
+
   // Hide message sidebar on the AI Assistant page itself
   const showMessageSidebar = !location.pathname.startsWith('/ai-assistant');
 
@@ -38,6 +43,7 @@ export function AppShell() {
       </div>
       {/* Message Sidebar — full height, right of TopBar and Toolbar */}
       {showMessageSidebar && <MessageSidebar />}
+      <AIUIControlIndicator />
       <ToastContainer />
     </div>
   );