test: 프론트엔드/백엔드 테스트 커버리지 및 시나리오 보강 (Issue #291)

- FE: Vitest 환경 구축 및 공통 UI 컴포넌트(Badge, Button) 테스트 추가
- FE: Playwright E2E 테스트(Auth, Tenant CRUD 및 Validation) 시나리오 보강
- BE: Testcontainers 기반 Repository 통합 테스트(PostgreSQL) 추가
- BE: TenantRepository 계층 구조(Hierarchy), DB 제약조건(Unique) 테스트
- BE: UserRepository 통합 테스트(CRUD, Delete) 추가
- BE: PasswordPolicy 유틸리티 테스트 보강
- BE: TenantService 엣지 케이스(중복 슬러그, 권한 등) 검증 로직 추가
- Fix: 하위 테넌트 생성 시 ParentID 누락 문제 해결

adminfront/src/components/ui/badge.test.tsx

@@ -0,0 +1,26 @@
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it } from "vitest";
+import { Badge } from "./badge";
+
+describe("Badge Component", () => {
+  it("renders correctly with children", () => {
+    render(<Badge>Active</Badge>);
+    expect(screen.getByText("Active")).toBeInTheDocument();
+  });
+
+  it("applies variant classes correctly", () => {
+    const { rerender } = render(<Badge variant="secondary">Secondary</Badge>);
+    let badge = screen.getByText("Secondary");
+    expect(badge).toHaveClass("bg-secondary");
+
+    rerender(<Badge variant="outline">Default</Badge>);
+    badge = screen.getByText("Default");
+    expect(badge).toHaveClass("text-foreground");
+  });
+
+  it("applies custom className", () => {
+    render(<Badge className="custom-class">Custom</Badge>);
+    const badge = screen.getByText("Custom");
+    expect(badge).toHaveClass("custom-class");
+  });
+});

adminfront/src/components/ui/button.test.tsx

@@ -0,0 +1,36 @@
+import { render, screen } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import { describe, expect, it, vi } from "vitest";
+import { Button } from "./button";
+
+describe("Button Component", () => {
+  it("renders correctly with children", () => {
+    render(<Button>Click me</Button>);
+    expect(screen.getByRole("button", { name: /click me/i })).toBeInTheDocument();
+  });
+
+  it("applies variant classes correctly", () => {
+    const { rerender } = render(<Button variant="destructive">Delete</Button>);
+    const button = screen.getByRole("button", { name: /delete/i });
+    expect(button).toHaveClass("bg-destructive");
+
+    rerender(<Button variant="outline">Cancel</Button>);
+    const outlineButton = screen.getByRole("button", { name: /cancel/i });
+    expect(outlineButton).toHaveClass("border-input");
+  });
+
+  it("calls onClick when clicked", async () => {
+    const onClick = vi.fn();
+    const user = userEvent.setup();
+    render(<Button onClick={onClick}>Click me</Button>);
+    
+    await user.click(screen.getByRole("button", { name: /click me/i }));
+    expect(onClick).toHaveBeenCalledTimes(1);
+  });
+
+  it("is disabled when the disabled prop is passed", () => {
+    render(<Button disabled>Disabled Button</Button>);
+    const button = screen.getByRole("button", { name: /disabled button/i });
+    expect(button).toBeDisabled();
+  });
+});