email service and template using resend

app/admin/system/page.tsx

@@ -55,7 +55,7 @@ async function getJobSummary(jobName: string): Promise<JobSummary> {
 }
 
 // Daftar cron yang dipantau. Tambah entry baru saat menambah cron route handler.
-const TRACKED_JOBS = ["auto-complete-trips"] as const;
+const TRACKED_JOBS = ["auto-complete-trips", "process-email-jobs"] as const;
 
 function healthOf(summary: JobSummary): "ok" | "stale" | "failed" {
   if (summary.lastRun?.status === "FAILED") return "failed";

app/api/cron/process-email-jobs/route.ts

@@ -0,0 +1,36 @@
+import { NextRequest, NextResponse } from "next/server";
+import { emailService } from "@/lib/email/send";
+import { runCron } from "@/lib/cron-runner";
+
+export const runtime = "nodejs";
+export const dynamic = "force-dynamic";
+
+/**
+ * Cron — proses retry queue email (jobs status PENDING/FAILED dengan
+ * attempts<5 dan scheduledAt sudah lewat).
+ *
+ * Trigger setiap 5 menit via system crontab — lihat docs/CRON_SETUP.md.
+ * Header wajib: `Authorization: Bearer ${CRON_SECRET}`.
+ */
+export async function GET(req: NextRequest) {
+  const secret = process.env.CRON_SECRET;
+  if (!secret) {
+    return NextResponse.json(
+      { error: "Server misconfigured (CRON_SECRET)" },
+      { status: 500 }
+    );
+  }
+  const authHeader = req.headers.get("authorization");
+  if (authHeader !== `Bearer ${secret}`) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  const outcome = await runCron("process-email-jobs", async () => {
+    return emailService.processQueue(50);
+  });
+
+  if (!outcome.ok) {
+    return NextResponse.json({ error: outcome.error }, { status: 500 });
+  }
+  return NextResponse.json({ ok: true, ...outcome.payload });
+}