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

app/plugins/builtins/kommunikation/schemas.py

@@ -24,6 +24,7 @@ class ConversationCreate(BaseModel):
     participant_types: list[str] = Field(default_factory=lambda: ["user"])
     initial_message: str | None = None
     is_direct: bool = False
+    metadata: dict[str, Any] = Field(default_factory=dict)
 
 
 class ConversationUpdate(BaseModel):