fix: remove remaining /api/ double-prefix from template literal API calls

Previous fix missed backtick template strings. Fixed 7 more api.*()
calls in appointments, deadlines, settings, and einstellungen pages.

frontend/src/components/settings/CalDAVSettings.tsx

@@ -68,7 +68,7 @@ export function CalDAVSettings({ tenant }: { tenant: Tenant }) {
         typeof window !== "undefined"
           ? localStorage.getItem("kanzlai_tenant_id")
           : null;
-      return api.put<Tenant>(`/api/tenants/${tenantId}/settings`, {
+      return api.put<Tenant>(`/tenants/${tenantId}/settings`, {
         caldav: cfg,
       });
     },

frontend/src/components/settings/TeamSettings.tsx

@@ -32,13 +32,13 @@ export function TeamSettings() {
   } = useQuery({
     queryKey: ["tenant-members", tenantId],
     queryFn: () =>
-      api.get<UserTenant[]>(`/api/tenants/${tenantId}/members`),
+      api.get<UserTenant[]>(`/tenants/${tenantId}/members`),
     enabled: !!tenantId,
   });
 
   const inviteMutation = useMutation({
     mutationFn: (data: { email: string; role: string }) =>
-      api.post(`/api/tenants/${tenantId}/invite`, data),
+      api.post(`/tenants/${tenantId}/invite`, data),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ["tenant-members"] });
       setEmail("");
@@ -52,7 +52,7 @@ export function TeamSettings() {
 
   const removeMutation = useMutation({
     mutationFn: (userId: string) =>
-      api.delete(`/api/tenants/${tenantId}/members/${userId}`),
+      api.delete(`/tenants/${tenantId}/members/${userId}`),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ["tenant-members"] });
       toast.success("Mitglied entfernt");