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/features/tenants/routes/TenantSchemaPage.tsx

@@ -97,7 +97,6 @@ export function TenantSchemaPage() {
 
   useEffect(() => {
     const rawSchema = tenantQuery.data?.config?.userSchema;
-    const loginIdField = tenantQuery.data?.config?.loginIdField;
 
     if (Array.isArray(rawSchema)) {
       setFields(
@@ -118,7 +117,7 @@ export function TenantSchemaPage() {
           validation:
             typeof field?.validation === "string" ? field.validation : "",
           unsigned: Boolean(field?.unsigned),
-          isLoginId: field?.key === loginIdField,
+          isLoginId: Boolean(field?.isLoginId),
         })),
       );
     }
@@ -126,13 +125,13 @@ export function TenantSchemaPage() {
 
   const updateMutation = useMutation({
     mutationFn: (newFields: SchemaField[]) => {
-      const loginIdField = newFields.find((f) => f.isLoginId)?.key || "";
+      // Remove legacy loginIdField, keep isLoginId natively in userSchema
+      const newConfig = { ...tenantQuery.data?.config };
+      delete newConfig.loginIdField;
+      newConfig.userSchema = newFields;
+
       return updateTenant(tenantId, {
-        config: {
-          ...tenantQuery.data?.config,
-          userSchema: newFields,
-          loginIdField: loginIdField,
-        },
+        config: newConfig,
       });
     },
     onSuccess: () => {
@@ -344,14 +343,10 @@ export function TenantSchemaPage() {
                   <label className="flex items-center gap-2 cursor-pointer">
                     <input
                       type="checkbox"
-                      checked={field.isLoginId}
-                      onChange={(e) => {
-                        const newFields = fields.map((f, i) => ({
-                          ...f,
-                          isLoginId: i === index ? e.target.checked : false,
-                        }));
-                        setFields(newFields);
-                      }}
+                      checked={field.isLoginId || false}
+                      onChange={(e) =>
+                        updateField(index, { isLoginId: e.target.checked })
+                      }
                       className="w-4 h-4 rounded border-gray-300 text-primary focus:ring-primary"
                     />
                     <span className="text-sm font-medium text-blue-600">

adminfront/src/features/users/UserCreatePage.tsx

@@ -31,6 +31,7 @@ type UserSchemaField = {
   required?: boolean;
   adminOnly?: boolean;
   validation?: string;
+  isLoginId?: boolean;
 };
 
 type UserFormValues = UserCreateRequest & { metadata: Record<string, unknown> };
@@ -65,7 +66,6 @@ function UserCreatePage() {
   } = useForm<UserFormValues>({
     defaultValues: {
       email: "",
-      loginId: "",
       password: "",
       name: "",
       phone: "",
@@ -274,26 +274,6 @@ function UserCreatePage() {
               )}
             </div>
 
-            <div className="space-y-2">
-              <Label htmlFor="loginId">
-                {t("ui.admin.users.create.form.login_id", "로그인 ID (선택)")}
-              </Label>
-              <Input
-                id="loginId"
-                placeholder={t(
-                  "ui.admin.users.create.form.login_id_placeholder",
-                  "사번 또는 아이디",
-                )}
-                {...register("loginId")}
-              />
-              <p className="text-[10px] text-muted-foreground">
-                {t(
-                  "msg.admin.users.create.form.login_id_help",
-                  "이메일/전화번호 외에 별도의 식별자로 로그인할 때 사용합니다.",
-                )}
-              </p>
-            </div>
-
             <div className="space-y-2">
               <div className="flex items-center justify-between">
                 <Label htmlFor="password">
@@ -470,6 +450,11 @@ function UserCreatePage() {
                             Admin Only
                           </span>
                         )}
+                        {field.isLoginId && (
+                          <span className="ml-2 text-[10px] bg-green-500/10 text-green-600 px-1.5 py-0.5 rounded uppercase font-bold">
+                            {t("ui.admin.users.create.form.is_login_id", "로그인 ID")}
+                          </span>
+                        )}
                       </Label>
 
                       <Input

adminfront/src/features/users/UserListPage.tsx

@@ -430,9 +430,6 @@ function UserListPage() {
                         "NAME / EMAIL",
                       )}
                     </TableHead>
-                    <TableHead>
-                      {t("ui.admin.users.list.table.login_id", "LOGIN ID")}
-                    </TableHead>
                     <TableHead>
                       {t("ui.admin.users.list.table.role", "ROLE")}
                     </TableHead>
@@ -514,11 +511,6 @@ function UserListPage() {
                           </div>
                         </div>
                       </TableCell>
-                      <TableCell>
-                        <span className="text-sm font-mono">
-                          {user.loginId || "-"}
-                        </span>
-                      </TableCell>
                       <TableCell>
                         <Badge variant="outline">
                           {t(`ui.admin.role.${user.role}`, user.role)}

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;