fix: replace deprecated *ngIf with @if control flow in OTP component

- Migrated all *ngIf directives to modern @if syntax in otp.component.html
- Updated email form, OTP entry, countdown display, and success message conditionals
- Resolves ngtsc deprecation warning 6385 for better Angular 17+ compatibility

src/app/auth/otp/otp.component.spec.ts

@@ -0,0 +1,23 @@
+import { ComponentFixture, TestBed } from '@angular/core/testing';
+
+import { OtpComponent } from './otp.component';
+
+describe('OtpComponent', () => {
+  let component: OtpComponent;
+  let fixture: ComponentFixture<OtpComponent>;
+
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      imports: [OtpComponent]
+    })
+    .compileComponents();
+
+    fixture = TestBed.createComponent(OtpComponent);
+    component = fixture.componentInstance;
+    fixture.detectChanges();
+  });
+
+  it('should create', () => {
+    expect(component).toBeTruthy();
+  });
+});