fix: prisma connection exhaustion & firebase lazy init

- prisma/schema.prisma: tambah binaryTargets debian & linux-musl untuk Docker
- src/lib/prisma.ts: pakai global singleton di dev & prod, hapus eager $connect()
- src/lib/firebase-admin.ts: lazy initialization agar tidak crash saat build time
- .env.example: lengkap dengan semua env variable + connection_limit & pool_timeout

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

src/lib/prisma.ts

@@ -1,115 +1,21 @@
 import { PrismaClient } from "@prisma/client";
 
-// Deklarasikan variabel global untuk menandai apakah listener sudah ditambahkan
 declare global {
-  var prisma: PrismaClient;
-  var prismaListenersAdded: boolean; // Flag untuk menandai listener
+  var prisma: PrismaClient | undefined;
 }
 
-let prisma: PrismaClient;
-
-// Validasi DATABASE_URL sebelum inisialisasi
 if (!process.env.DATABASE_URL) {
-  console.error('❌ ERROR: DATABASE_URL tidak ditemukan di environment variables!');
-  console.error('');
-  console.error('Current working directory:', process.cwd());
-  console.error('Available environment variables:', Object.keys(process.env).sort().join(', '));
-  console.error('');
-  console.error('Solusi:');
-  console.error('  1. Pastikan file .env ada dan berisi DATABASE_URL, ATAU');
-  console.error('  2. Set DATABASE_URL di system environment:');
-  console.error('     export DATABASE_URL="postgresql://user:pass@host:port/dbname"');
-  console.error('  3. Jika menggunakan systemd service, tambahkan di file service:');
-  console.error('     [Service]');
-  console.error('     Environment=DATABASE_URL=postgresql://...');
-  console.error('');
-  throw new Error('DATABASE_URL is required but not found in environment variables');
+  throw new Error("DATABASE_URL is required but not found in environment variables");
 }
 
-if (process.env.NODE_ENV === "production") {
-  prisma = new PrismaClient({
-    // Reduce logging in production to improve performance
-    log: ['error', 'warn'],
-    datasources: {
-      db: {
-        url: process.env.DATABASE_URL,
-      },
-    },
+const prisma =
+  global.prisma ??
+  new PrismaClient({
+    log: process.env.NODE_ENV === "development" ? ["error", "warn", "query"] : ["error", "warn"],
   });
 
-  // Explicitly connect to database dengan retry
-  const maxRetries = 3;
-  let retryCount = 0;
-  
-  const connectWithRetry = async () => {
-    while (retryCount < maxRetries) {
-      try {
-        await prisma.$connect();
-        console.log('✅ PostgreSQL connected successfully');
-        return;
-      } catch (error) {
-        retryCount++;
-        const errorMsg = error instanceof Error ? error.message : 'Unknown error';
-        console.error(`❌ PostgreSQL connection attempt ${retryCount}/${maxRetries} failed:`, errorMsg);
-        
-        if (retryCount >= maxRetries) {
-          console.error('❌ All database connection attempts failed. Application will continue but database operations will fail.');
-          throw error;
-        }
-        
-        // Wait before retry (exponential backoff)
-        const waitTime = Math.min(1000 * Math.pow(2, retryCount), 10000);
-        console.log(`⏳ Retrying in ${waitTime}ms...`);
-        await new Promise(resolve => setTimeout(resolve, waitTime));
-      }
-    }
-  };
-
-  // Initialize connection (non-blocking)
-  connectWithRetry().catch(err => {
-    console.error('Failed to initialize database connection:', err);
-  });
-
-} else {
-  if (!global.prisma) {
-    global.prisma = new PrismaClient({
-      log: ['error', 'warn', 'info', 'query'], // More verbose logging in development
-      datasources: {
-        db: {
-          url: process.env.DATABASE_URL,
-        },
-      },
-    });
-  }
-  prisma = global.prisma;
-}
-
-// Tambahkan listener hanya jika belum ditambahkan sebelumnya
-if (!global.prismaListenersAdded) {
-  // Handle graceful shutdown
-  process.on("SIGINT", async () => {
-    console.log("Received SIGINT signal. Closing database connections...");
-    await prisma.$disconnect();
-    process.exit(0);
-  });
-
-  process.on("SIGTERM", async () => {
-    console.log("Received SIGTERM signal. Closing database connections...");
-    await prisma.$disconnect();
-    process.exit(0);
-  });
-
-  // Handle uncaught errors
-  process.on("uncaughtException", async (error) => {
-    if (error.message.includes("Prisma") || error.message.includes("database")) {
-      console.error("Uncaught database error:", error);
-      await prisma.$disconnect();
-    }
-  });
-
-  // Tandai bahwa listener sudah ditambahkan
-  global.prismaListenersAdded = true;
-}
+// Selalu assign ke global agar hanya ada 1 instance (dev: cegah hot-reload, prod: cegah multiple instances)
+global.prisma = prisma;
 
 export default prisma;
 export { prisma };