Verify the Angular 21 code practices updation

1. Replace `HttpClientModule` with `provideHttpClient(withFetch(), withInterceptors(...))`. Convert the two interceptors to functions.

Every HttpClient call. Network Type should be fetch, not xhr.
Logged-in API calls. authorization still has to show up on users/ and post/ requests.
401 refresh. Poison fm_user, keep fm_over. You should see PUT users/users/refresh-token, then the original call with a new token.
403 logout, private-content 400, /user_by_username suspend/private, and /users/users?host_name creator logout.
The subscription-plan call that uses skipInterceptor=true.
SSR and prerender HTTP. Fetch is the server path. An XHR error on the server means this did not take.
Upload percent bars on lesson video, post image, merch, and the other reportProgress flows. Fetch does not emit upload percent. The file can still land. The bar can sit at 0 and then jump.
Selects that load options from a URL or a JSON file.