feat: NCWF-5/6/7/8/9 chess analysis page and engine integration (#11)

Co-authored-by: Janis Eccarius <eccariusjanis@gmail.com>
Reviewed-on: #11

src/app/services/official-bot.service.ts

@@ -0,0 +1,22 @@
+import { Injectable, inject } from '@angular/core';
+import { HttpClient } from '@angular/common/http';
+import { Observable } from 'rxjs';
+
+export interface JoinTournamentResponse {
+  botId: string;
+  difficulty: string;
+  status: string;
+}
+
+@Injectable({ providedIn: 'root' })
+export class OfficialBotService {
+  private readonly http = inject(HttpClient);
+  private readonly base = '/api/bots/official';
+
+  joinTournament(tournamentId: string, difficulty: string): Observable<JoinTournamentResponse> {
+    return this.http.post<JoinTournamentResponse>(`${this.base}/join-tournament`, {
+      tournamentId,
+      difficulty,
+    });
+  }
+}