docs: update cron information

.env.sample

@@ -8,6 +8,10 @@ DC_API_KEY=
 # https://console.upstash.com/qstash
 QSTASH_CURRENT_SIGNING_KEY=
 QSTASH_NEXT_SIGNING_KEY=
+# Qstash can be removed if using Vercel Cron
+# https://vercel.com/docs/cron-jobs/quickstart
+# DC cron endpoint: frame/send-notifications
+# /frame/[[...routes]]/route.tsx line 44 - 61 can be removed and verified with vercel cron env
 
 NEXT_PUBLIC_SITE_URL=
 NEXT_PUBLIC_GOOGLE_ANALYTICS_ID=

app/frame/[[...routes]]/route.tsx

@@ -49,25 +49,25 @@ app.hono.post("/send-notifications", async (c) => {
   }
   const body = await c.req.text();
   const currentDay = getCurrentDateUTC();
+
+  const isValid = await qstashReceiver
+  .verify({
+    body,
+    signature,
+  })
+  .catch((e) => false);
+
+  if (!isValid) {
+    return c.json({ error: "Invalid signature" }, 400);
+  }
+
   const notificationMessage = `
   Day ${currentDay} NFT is now mintable!.
 
   ${config.PROD_URL}/frame/dc
   
   N/B: Unsubscribe from getting these notifications through the frame.
   `;
-
-  const isValid = await qstashReceiver
-    .verify({
-      body,
-      signature,
-    })
-    .catch((e) => false);
-
-  if (!isValid) {
-    return c.json({ error: "Invalid signature" }, 400);
-  }
-
   async function sendUserDCs() {
     // const userFids = [846887];
     const userFids = await kvStore.smembers(UNLOCK_REDIS_KEY);