feat: challange request, accept, decline, page, added (not complete, polling issues, and not stable, and too much code for nothing)

Co-authored-by: Copilot <copilot@github.com>

src/app/services/challenge-event.service.ts

@@ -0,0 +1,64 @@
+import { Injectable, inject } from '@angular/core';
+import { BehaviorSubject, Observable, Subject } from 'rxjs';
+import { Challenge } from '../models/challenge.models';
+
+/**
+ * Service to manage challenge events via WebSocket
+ * Listens for incoming challenges and emits them to subscribers
+ */
+@Injectable({ providedIn: 'root' })
+export class ChallengeEventService {
+  private readonly incomingChallenges$ = new BehaviorSubject<Challenge[]>([]);
+  private readonly challengeReceived$ = new Subject<Challenge>();
+  private readonly challengeAccepted$ = new Subject<Challenge>();
+  private readonly challengeDeclined$ = new Subject<Challenge>();
+
+  getIncomingChallenges$(): Observable<Challenge[]> {
+    return this.incomingChallenges$.asObservable();
+  }
+
+  getChallengeReceived$(): Observable<Challenge> {
+    return this.challengeReceived$.asObservable();
+  }
+
+  getChallengeAccepted$(): Observable<Challenge> {
+    return this.challengeAccepted$.asObservable();
+  }
+
+  getChallengeDeclined$(): Observable<Challenge> {
+    return this.challengeDeclined$.asObservable();
+  }
+
+  /**
+   * Called when a new challenge is received via WebSocket
+   */
+  onChallengeReceived(challenge: Challenge): void {
+    const current = this.incomingChallenges$.value;
+    this.incomingChallenges$.next([...current, challenge]);
+    this.challengeReceived$.next(challenge);
+  }
+
+  /**
+   * Called when a challenge is accepted
+   */
+  onChallengeAccepted(challenge: Challenge): void {
+    const current = this.incomingChallenges$.value;
+    this.incomingChallenges$.next(current.filter(c => c.id !== challenge.id));
+    this.challengeAccepted$.next(challenge);
+  }
+
+  /**
+   * Called when a challenge is declined or expires
+   */
+  onChallengeRemoved(challengeId: string): void {
+    const current = this.incomingChallenges$.value;
+    this.incomingChallenges$.next(current.filter(c => c.id !== challengeId));
+  }
+
+  /**
+   * Remove a challenge from the incoming list
+   */
+  removeChallenge(challengeId: string): void {
+    this.onChallengeRemoved(challengeId);
+  }
+}