Mijn aanvragen: list enter/leave animations + 204 null-body fix

- animate.enter/leave on aanvraag cards and upload rows (native Angular, no @angular/animations)
- reduced-motion: skip animation → instant removal
- api-client: null-body statuses (204/205/304) must pass null to Response()

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/shared/infrastructure/api-client.provider.ts

@@ -40,7 +40,9 @@ function httpClientFetch(http: HttpClient) {
             })
             .pipe(timeout(REQUEST_TIMEOUT_MS)),
         );
-        return new Response(res.body ?? '', { status: res.status || 200 });
+        // 204/205/304 are null-body statuses — new Response(body, …) throws for any non-null body.
+        const nullBody = res.status === 204 || res.status === 205 || res.status === 304;
+        return new Response(nullBody ? null : (res.body ?? ''), { status: res.status || 200 });
       } catch (e) {
         if (e instanceof TimeoutError) return new Response('', { status: 504 });
         const err = e as HttpErrorResponse;