feat: implement multi-identifier architecture (Issue #496)

- Database: Add user_login_ids table for 1:N identifier mapping and remove legacy login_id column
- Kratos: Update identity schema to use custom_login_ids array instead of a single id trait
- Backend: Implement syncCustomLoginIDs to collect isLoginId fields across tenant schemas
- Backend: Add backtracking logic to auto-assign session tenant based on used login identifier
- Backend: Add 409 Conflict exception handling for Create/Update operations
- AdminFront: Refactor UserDetailPage to a tabbed grid layout (Info, Tenants, Security)
- AdminFront: Show '로그인 ID' badge on tenant schema fields used for authentication
- UserFront: Remove legacy optional 'Login ID' input from signup flow
- Tests: Add multi-identifier repository tests and update handler tests

adminfront/src/lib/adminApi.ts

@@ -549,6 +549,20 @@ export async function deleteUser(userId: string) {
   await apiClient.delete(`/v1/admin/users/${userId}`);
 }
 
+export type UserRpHistoryItem = {
+  client_id: string;
+  client_name: string;
+  lastLoginAt: string;
+  status: string;
+};
+
+export async function fetchUserRpHistory(userId: string) {
+  const { data } = await apiClient.get<UserRpHistoryItem[]>(
+    `/v1/admin/users/${userId}/rp-history`,
+  );
+  return data;
+}
+
 export type UserProfileResponse = {
   id: string;
   email: string;