add loading and optimize query using cache and pwa

server/services/trip.service.ts

@@ -1,3 +1,4 @@
+import { cache } from "react";
 import { Prisma } from "@/app/generated/prisma/client";
 import type { ActivityCategory, Vibe } from "@/app/generated/prisma/enums";
 import { tripRepo, type TripFilters } from "@/server/repositories/trip.repo";
@@ -38,13 +39,18 @@ export const tripService = {
     return tripRepo.findAll();
   },
 
-  async getTripById(id: string) {
+  /**
+   * Ambil trip by id. Dibungkus `React.cache()` — `generateMetadata`, body
+   * halaman, dan `opengraph-image` memanggil ini untuk id yang sama dalam satu
+   * request, jadi query Prisma yang berat ini cukup jalan sekali per request.
+   */
+  getTripById: cache(async (id: string) => {
     const trip = await tripRepo.findById(id);
     if (!trip) {
       throw new Error("Trip tidak ditemukan");
     }
     return trip;
-  },
+  }),
 
   async createTrip(input: CreateTripInput) {
     if (isTripDepartureDayPast(input.date)) {