Notifications — who gets told what

Shipments notifies the right person for each event — once per event, never twice — over in-app, SMS, and email (SMS and email only when you gave that party a phone or address).

The events:
• On its way — when a package starts moving, the waiting recipient is told, with the ETA if the carrier gives one.
• Delivered — both the recipient and the shipper are told; the shipper's note says "No further action needed."
• Delivery exception — a stuck package, address problem, or customs hold notifies the shipper so someone can act.
• Ship-by nudge — the deadline reminders described in "Ship-by deadlines and the anti-hounding nudges".

Notifications are idempotent — each event is stamped once it's sent, so re-checking the carrier never re-notifies. Your org always keeps an in-app copy even when the other party is an outside person.

Manual controls on each card:
• Refresh now — force an immediate carrier check instead of waiting for the next scheduled poll.
• Send — message the other party directly (e.g. "Dropped at USPS this morning"); it reaches them in-app, by SMS, and by email.
• Stop tracking — close the shipment and stop watching it.