fix: notify professional via FCM when service is created

Backend create() now looks up the professional's fcm_token and sends a
push notification after the service is persisted. This replaces the
unreliable client-side notification in the Flutter app (which couldn't
use the server FCM key).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/services/services.service.ts

@@ -80,7 +80,7 @@ export class ServicesService {
       if (!inRange) throw new BadRequestException('La hora seleccionada está fuera del horario del profesional');
     }
 
-    return this.prisma.services.create({
+    const created = await this.prisma.services.create({
       data: {
         professional_id: prof.id,
         user_id: data.user_id,
@@ -95,6 +95,21 @@ export class ServicesService {
         location_preference: data.location_preference as any,
       },
     });
+
+    // Notify the professional of the new service request
+    const profUser = await this.prisma.users.findUnique({
+      where: { id: prof.user_id },
+      select: { fcm_token: true },
+    });
+    if (profUser?.fcm_token) {
+      this.notifications.send(
+        profUser.fcm_token,
+        'Nueva solicitud de servicio',
+        'Tienes una nueva solicitud pendiente de un cliente.',
+      ).catch(() => {});
+    }
+
+    return created;
   }
 
   async updateStatus(serviceId: string, newStatus: ServiceStatus, userId: string) {