Switch to localStorage for JWT handling and simplify case transformation logic in LoginComponent. Update app.config.ts and related services to align with the new token management method. Mark JwtClaims interface as exported.

frontend/src/app/app.config.ts

@@ -1,26 +1,29 @@
-import {ApplicationConfig, provideZoneChangeDetection} from '@angular/core';
+import {ApplicationConfig, importProvidersFrom, provideZoneChangeDetection} from '@angular/core';
 import {provideRouter} from '@angular/router';
 import {JwtHelperService, JwtModule} from '@auth0/angular-jwt';
 import {CookieService} from 'ngx-cookie-service';
 
 import {routes} from './app.routes';
 
-// Function to get the JWT token from cookies
 export function jwtTokenGetter() {
-  const cookieService = new CookieService(document, null);
-  return cookieService.check('jwt') ? cookieService.get('jwt') : null;
+  return localStorage.getItem('jwt');
 }
 
 export const appConfig: ApplicationConfig = {
   providers: [
     provideZoneChangeDetection({eventCoalescing: true}),
     provideRouter(routes),
-    { provide: CookieService, useClass: CookieService },
-    { provide: JwtHelperService, useClass: JwtHelperService },
-    { provide: JwtModule, useValue: JwtModule.forRoot({
-      config: {
-        tokenGetter: jwtTokenGetter
-      }
-    })}
+    CookieService,
+    {
+      provide: JwtHelperService,
+      useValue: new JwtHelperService()
+    },
+    importProvidersFrom(
+      JwtModule.forRoot({
+        config: {
+          tokenGetter: jwtTokenGetter
+        }
+      })
+    )
   ]
 };