feat: Implement core monetization features including course pricing, payment preference creation, and transaction management with Mercado Pago integration.

web/experience/src/lib/api.ts

@@ -55,9 +55,16 @@ export interface Course {
     pacing_mode: string;
     start_date?: string;
     end_date?: string;
+    price: number;
+    currency: string;
     created_at: string;
 }
 
+export interface PaymentPreferenceResponse {
+    preference_id: string;
+    init_point: string;
+}
+
 export interface QuizQuestion {
     id: string;
     question: string;
@@ -372,6 +379,13 @@ export const lmsApi = {
         return apiFetch(`/enrollments/${userId}`);
     },
 
+    async createPaymentPreference(courseId: string): Promise<PaymentPreferenceResponse> {
+        return apiFetch('/payments/preference', {
+            method: 'POST',
+            body: JSON.stringify({ course_id: courseId })
+        });
+    },
+
     async submitScore(userId: string, course_id: string, lessonId: string, score: number, metadata: Record<string, unknown> = {}): Promise<UserGrade> {
         return apiFetch('/grades', {
             method: 'POST',