fix(UI-Overhaul-Phase1): 7 Bugs behoben

1.1 Contacts refresh: useUnifiedContacts mutations already invalidate (verified)
1.2 Contacts drag-drop: ContactList items already draggable + ContactFolderTree onDrop (verified)
1.3 Contacts move dialog: Added move-to-folder dropdown in ContactDetail
1.4 Wiki save refresh: Added refreshKey prop to WikiBrowser, triggers reload after save/delete
1.5 Calendar dialog close: Window.tsx now injects windowId into componentProps
1.6 Communication AI chat: Added metadata support to ConversationCreate schema + service,
    frontend passes conversation_type metadata for AI/system chats,
    categorization checks metadata first
1.7 Wiki duplicate menu: Removed hardcoded /wiki from Sidebar.tsx (plugin provides it dynamically)

Backend: kommunikation schema/routes/services updated for metadata support
Frontend: tsc clean, build successful

frontend/src/pages/Communication.tsx

@@ -89,6 +89,10 @@ type ConversationCategory = 'system' | 'ai' | 'colleague';
 // ─── Helpers ───
 
 function categorizeConversation(conv: Conversation): ConversationCategory {
+  // Check metadata first (most reliable for AI/system chats)
+  const convType = conv.metadata?.conversation_type;
+  if (convType === 'system') return 'system';
+  if (convType === 'ai') return 'ai';
   // System messages: created by system participant type
   if (conv.participants.some(p => p.participant_type === 'system')) return 'system';
   // AI conversations: have an AI participant
@@ -136,12 +140,13 @@ async function sendMessage(convId: string, content: string, replyToId?: string):
   return r.data;
 }
 
-async function createConversation(title: string | null, participantIds: string[], isDirect: boolean, initialMessage?: string): Promise<Conversation> {
+async function createConversation(title: string | null, participantIds: string[], isDirect: boolean, initialMessage?: string, metadata?: Record<string, unknown>): Promise<Conversation> {
   const r = await apiClient.post('/comm/conversations', {
     title,
     participant_ids: participantIds,
     is_direct: isDirect,
     initial_message: initialMessage,
+    metadata: metadata || {},
   });
   return r.data;
 }
@@ -781,7 +786,11 @@ export function CommunicationPage() {
     try {
       const category = showNewChat;
       const isDirect = category === 'colleague' && participantIds.length === 1;
-      const conv = await createConversation(title || null, participantIds, isDirect);
+      const metadata: Record<string, unknown> =
+        category === 'ai' ? { conversation_type: 'ai' } :
+        category === 'system' ? { conversation_type: 'system' } :
+        {};
+      const conv = await createConversation(title || null, participantIds, isDirect, undefined, metadata);
       setConversations(prev => [...prev, conv]);
       setActiveConvId(conv.id);
       setMobileView('chat');