fix data flow issues

apps/website/lib/api/sponsors/SponsorsApiClient.ts

@@ -63,4 +63,41 @@ export class SponsorsApiClient extends BaseApiClient {
   rejectSponsorshipRequest(requestId: string, input: RejectSponsorshipRequestInputDTO): Promise<void> {
     return this.post(`/sponsors/requests/${requestId}/reject`, input);
   }
+
+  /** Get sponsor billing information */
+  getBilling(sponsorId: string): Promise<{
+    paymentMethods: any[];
+    invoices: any[];
+    stats: any;
+  }> {
+    return this.get(`/sponsors/billing/${sponsorId}`);
+  }
+
+  /** Get available leagues for sponsorship */
+  getAvailableLeagues(): Promise<any[]> {
+    return this.get('/sponsors/leagues/available');
+  }
+
+  /** Get detailed league information */
+  getLeagueDetail(leagueId: string): Promise<{
+    league: any;
+    drivers: any[];
+    races: any[];
+  }> {
+    return this.get(`/sponsors/leagues/${leagueId}/detail`);
+  }
+
+  /** Get sponsor settings */
+  getSettings(sponsorId: string): Promise<{
+    profile: any;
+    notifications: any;
+    privacy: any;
+  }> {
+    return this.get(`/sponsors/settings/${sponsorId}`);
+  }
+
+  /** Update sponsor settings */
+  updateSettings(sponsorId: string, input: any): Promise<void> {
+    return this.put(`/sponsors/settings/${sponsorId}`, input);
+  }
 }