feat(watches): show the carrier's expected delivery date

[Aswinmcw]

Blue Dart and Delhivery both publish an expected delivery date, and the public track page has always displayed it — but a watch never stored it, so the dashboard and the alert emails couldn't. This persists it and surfaces it in both places.

Changes

migrations/0010 — watches.estimated_delivery (TEXT, nullable). Stored as the carrier renders it ("30 Aug 2026") rather than parsed into a date: each carrier formats it differently and it is only ever displayed verbatim, exactly as src/app/track/.../page.tsx already does.

Poller — refreshes it on every successful poll, not only when a scan changes. Carriers revise the date without adding an event, so tying the write to status changes would leave a stale date sitting on the dashboard for days. It is written only when the carrier actually returned one, so a single flaky scrape can't wipe a date we already know — bluedart.ts is an HTML scraper, so that failure mode is real.

Alert email — an "Expected delivery" row in the shipment card, plus a line in the plain-text part. Falls back to the stored value when the poll that triggered the alert didn't return one.

Dashboard — a muted line under the status pill:

in transit
expected 30 Aug 2026

mirroring the existing "auto-removes in N days" note, and hidden once a shipment is delivered or cancelled, where an expected date is only noise. Deliberately not a new column — the table is already 7 wide inside a 960px container and this file has a history of layout fixes (c52ce4a, 9dd0d90).

Shiprocket publishes no ETA, so those watches simply show nothing.

Verification

Email template, compiled and rendered directly:

PASS  html shows the Expected delivery label
PASS  html shows the date
PASS  text shows it too
PASS  subject unchanged by the ETA change
PASS  no ETA -> label absent from html
PASS  no ETA -> label absent from text
PASS  no ETA -> email still renders
PASS  null ETA treated as absent
PASS  ETA is html-escaped

Dashboard, rendered for real against local D1 with three seeded watches:

active WITH eta      row_found=True   shows_eta=True
  ...21101427141 bluedart In flight in transit expected 30 Aug 2026 Every 15 minutes...
active WITHOUT eta   row_found=True   shows_eta=False
completed WITH eta   excluded (finished watches hide the ETA)

tsc --noEmit clean, poller bundles at 50.35 KiB, opennextjs-cloudflare build green.

Rollout

Migration 0010 is already applied to local and remote D1, ahead of this landing, so the column exists before any code reads or writes it. Adding it was additive and nullable; existing rows read NULL and backfill on their next poll.

Two halves land at different times, because the poller's production deploy is still disabled (its "Deploy default branch" trigger runs wrangler versions upload instead of wrangler deploy):

• dashboard — live as soon as this merges and the web worker deploys, but the column is NULL for every existing watch until a poller carrying this change writes to it
• ETA in emails, and populating the column — needs the poller deployed: either restore that trigger's deploy command to npx wrangler deploy -c wrangler.poller.jsonc, or run npm run deploy:poller once

[Aswincloud-Bot]

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