Add Prettier for TypeScript formatting

- Install prettier
- Configure .prettierrc.json and .prettierignore
- Add npm scripts: format, format:check
- Add Makefile target: format-frontend
- Format all frontend files

frontend/app/audit/page.test.tsx

@@ -17,12 +17,10 @@ let mockUser: { id: number; email: string; roles: string[]; permissions: string[
 };
 let mockIsLoading = false;
 const mockLogout = vi.fn();
-const mockHasPermission = vi.fn((permission: string) =>
-  mockUser?.permissions.includes(permission) ?? false
-);
-const mockHasRole = vi.fn((role: string) =>
-  mockUser?.roles.includes(role) ?? false
+const mockHasPermission = vi.fn(
+  (permission: string) => mockUser?.permissions.includes(permission) ?? false
 );
+const mockHasRole = vi.fn((role: string) => mockUser?.roles.includes(role) ?? false);
 
 vi.mock("../auth-context", () => ({
   useAuth: () => ({
@@ -53,12 +51,10 @@ beforeEach(() => {
     permissions: ["view_audit"],
   };
   mockIsLoading = false;
-  mockHasPermission.mockImplementation((permission: string) =>
-    mockUser?.permissions.includes(permission) ?? false
-  );
-  mockHasRole.mockImplementation((role: string) =>
-    mockUser?.roles.includes(role) ?? false
+  mockHasPermission.mockImplementation(
+    (permission: string) => mockUser?.permissions.includes(permission) ?? false
   );
+  mockHasRole.mockImplementation((role: string) => mockUser?.roles.includes(role) ?? false);
   // Default: successful empty response
   mockFetch.mockResolvedValue({
     ok: true,
@@ -142,7 +138,7 @@ describe("AuditPage", () => {
       per_page: 10,
       total_pages: 1,
     };
-    
+
     const sumResponse = {
       records: [],
       total: 0,