Fix scheduled WhatsApp messages sending as email; add 24h cleanup and recipient display

The scheduled-job store never persisted the channel field, so the
send worker always fell through to its email branch regardless of
what was requested. Also purges sent jobs 24h after sending instead
of keeping them forever, and surfaces who each scheduled job will go
to in the admin "manage scheduled" lists (now correctly filtered per
channel too).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backend/src/controllers/scheduledEmailsController.js

@@ -11,6 +11,8 @@ function toClient(job) {
     kind,
     eventId: job.eventId || null,
     broadcast: !!job.broadcast,
+    channel: job.channel || 'email',
+    recipient: job.recipientSummary || null,
     scheduledAt: job.scheduledAt,
     createdAt: job.createdAt,
     status: job.status,
@@ -23,21 +25,13 @@ function toClient(job) {
   };
 }
 
-// GET /api/scheduled-emails
-// Returns jobs excluding emails sent more than a week ago
+// GET /api/scheduled-emails?channel=email|whatsapp
+// Sent jobs are purged from storage 24h after sending, so nothing older than that is ever returned here
 const listScheduledEmails = async (req, res) => {
   try {
-    const raw = listJobs();
-    const now = new Date();
-    const weekMs = 7 * 24 * 60 * 60 * 1000;
-    const filtered = raw.filter(j => {
-      if (j.status === 'sent' && j.sentAt) {
-        const sentAt = new Date(j.sentAt).getTime();
-        return (now.getTime() - sentAt) <= weekMs;
-      }
-      // Include queued, sending, error by default
-      return true;
-    })
+    const { channel } = req.query || {};
+    const raw = listJobs(channel ? { channel: String(channel) } : {});
+    const filtered = raw
     // Provide most-relevant first: queued -> sending -> error -> recent sent
     .sort((a, b) => {
       const order = { queued: 0, sending: 1, error: 2, sent: 3 };