fix(stcourier): use the newest scan as the headline status

[Aswinmcw]

Two fixes from the first live multi-scan ST Courier shipment (AWB 64424565531).

1. Headline status lagged the scan list

ST Courier's "Current Status" summary cell is not kept in sync with their own timeline:

summary cell      : In Transit
latest scan       : Out for Delivery   (Sep 04, 2026 10:31 AM)

#25 preferred that cell, so /api/track/stcourier/... and the public tracking page reported in_transit while rendering an Out for Delivery scan directly beneath it.

Now prefers the newest scan — matching the Blue Dart carrier — with the summary cell kept only as a fallback for shipments that have no scans yet.

before → headline status: in_transit       (latest scan: out_for_delivery)
after  → headline status: out_for_delivery (latest scan: out_for_delivery)

This did not affect alerting or delivered-detection: the poller already keys lastKnownStatus and the TERMINAL check off latest.status, not result.status.

2. Poller skipped unknown carriers silently

The poller is deployed separately from the web app (npm run deploy:poller, no CI workflow), so a carrier added to the registry goes live on the site while shiptrack-poller still runs the previous bundle. In that window:

const carrier = getCarrier(w.carrier);
if (!carrier) { await markPolled(env.DB, w.id); return; }

markPolled stamps last_polled_at but leaves last_known_status null — so the dashboard shows "awaiting first scan" forever with a fresh last-poll timestamp, no alerts fire, and nothing appears in the logs. That's exactly what happened to the first ST Courier watch after #25 merged.

This adds a console.warn naming the watch and carrier. It doesn't change behaviour — skipping is still correct — it just makes the stale-deploy window diagnosable.

Also confirmed

The open question from #25 — ST Courier's scan render order — is now settled against a 3-scan shipment. parseScans returns correct oldest-first ordering:

[0] Sep 03, 2026 10:49 PM | in_transit       | Processed & Forwarded to Hub
[1] Sep 04, 2026 10:29 AM | in_transit       | Processed & Forwarded to Service Center
[2] Sep 04, 2026 10:31 AM | out_for_delivery | Out for Delivery

tsc --noEmit clean.

Note: merging this does not fix the stuck watch on its own — shiptrack-poller still needs npm run deploy:poller to pick up the ST Courier carrier.

🤖 Generated with Claude Code

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Status	Name	Latest Commit	Preview URL	Updated (UTC)
✅ Deployment successful! View logs	shiptrack	0fa66a0	Commit Preview URL Branch Preview URL	Sep 04 2026, 10:29 AM

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Auto-approved: @Aswinmcw is a member of @Aswincloud/admins.

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