feat(auth): implement authentication service, guards, and interceptors

- Add AuthService for handling login, registration, and session management.
- Create auth guards to protect routes based on authentication status.
- Implement auth interceptor to attach JWT token to HTTP requests and handle 401 errors.
- Add unit tests for AuthService, guards, and interceptor.
- Create login and registration components with form validation and error handling.
- Update routing to include guards for login and registration pages.

src/app/features/store/store.routes.ts

@@ -2,6 +2,7 @@ import { Routes } from '@angular/router';
 
 import { AuthLayoutComponent } from '../../core/layout/auth-layout/auth-layout.component';
 import { StoreLayoutComponent } from '../../core/layout/store-layout/store-layout.component';
+import { guestOnlyGuard } from '../../core/services/auth/auth.guards';
 import { LoginPageComponent } from './pages/login-page/login-page.component';
 import { RegisterPageComponent } from './pages/register-page/register-page.component';
 import { StoreHomePageComponent } from './pages/store-home-page/store-home-page.component';
@@ -17,6 +18,7 @@ export const routes: Routes = [
       },
       {
         path: 'login',
+        canActivate: [guestOnlyGuard],
         component: AuthLayoutComponent,
         children: [
           {
@@ -27,6 +29,7 @@ export const routes: Routes = [
       },
       {
         path: 'register',
+        canActivate: [guestOnlyGuard],
         component: AuthLayoutComponent,
         children: [
           {