invoice: a reusable bolt12 offer has no terminal paid state

A bolt12 offer is a standing payment code. CLN derives the same offer_id
from the same (amount, description), so re-creating one hands back the
original record, whose `received` has accumulated over the offer's whole
lifetime. The invoice layout read that as "this invoice was paid" and
redirected to the success screen, so reopening a long-lived offer never
showed the QR and left no way to copy the lno.

Treat a payment as celebratory only when it arrives while the page is
open: the socket handler now passes the amount of that payment as
`?paid=<amount>`, and the layout uses it in place of the lifetime total
for reusable offers. Single-use invoices keep the existing logic, so a
partly-paid invoice still stays on the QR rather than celebrating early.

The success screen showed lifetime `received` for the same reason, which
misreported a single payment to a long-lived offer; it now renders the
amount the socket reported, which is already net of tip.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/lib/socket.ts b/src/lib/socket.ts
index b87cc165..b28b1060 100644
--- a/src/lib/socket.ts
+++ b/src/lib/socket.ts
@@ -57,7 +57,12 @@ export const messages = (data) => ({
 				pathname.includes("/receive") ||
 				pathname.includes("/invoice")
 			) {
-				if (!get(navigating)) goto(`/invoice/${iid}`);
+				// `paid=<amount>` marks this as a payment that arrived just now, and
+				// carries the amount of THIS payment. A reusable bolt12 offer needs
+				// both: its `received` is a lifetime total, so the invoice layout
+				// can't tell a live payment from an old one, and the success screen
+				// would otherwise show the accumulated figure.
+				if (!get(navigating)) goto(`/invoice/${iid}?paid=${amount}`);
 			} else success(`${confirmed ? "Received" : "Detected"} ⚡️${s(amount)}!`);
 		}
 	},