feat: implement multi-tenant member management and UI improvements

- Add multi-tenant support (isAddTenant, isRemoveTenant) to backend UpdateUser API.
- Update UserRepository to support searching in company_codes array.
- Implement table sorting and align search bar layout in adminfront.
- Add 'Assign Existing Member' and 'Exclude from Organization' features to TenantUsersPage.
- Auto-populate tenantSlug in UserCreatePage via query parameters.
- Add necessary localization keys for new UI elements.

Resolves #644, #639, #642, #641

adminfront/src/features/users/UserCreatePage.tsx

@@ -11,7 +11,7 @@ import {
 } from "lucide-react";
 import * as React from "react";
 import { useForm } from "react-hook-form";
-import { Link, useNavigate } from "react-router-dom";
+import { Link, useNavigate, useSearchParams } from "react-router-dom";
 import { Button } from "../../components/ui/button";
 import {
   Card,
@@ -104,6 +104,7 @@ function createEmptyAppointment(): AppointmentDraft {
 
 function UserCreatePage() {
   const navigate = useNavigate();
+  const [searchParams] = useSearchParams();
   const queryClient = useQueryClient();
   const [error, setError] = React.useState<string | null>(null);
   const [generatedPassword, setGeneratedPassword] = React.useState<
@@ -144,7 +145,7 @@ function UserCreatePage() {
       password: "",
       name: "",
       phone: "",
-      tenantSlug: "",
+      tenantSlug: searchParams.get("tenantSlug") ?? "",
       department: "",
       position: "",
       jobTitle: "",