use payments/sse on the core wallet UI.

still fallback to the invoice polling (now with a 5 seconds interval
because less than that is too annoying).

this fixes issues with /lnurlwallet invoices not getting paid in time,
so we update the UI automatically when they do get paid.

(see https://t.me/lnbits/7069)

lnbits/static/js/base.js

@@ -63,6 +63,19 @@ window.LNbits = {
       )
     }
   },
+  events: {
+    onInvoicePaid: function (wallet, cb) {
+      if (!this.pis) {
+        this.pis = new EventSource(
+          '/api/v1/payments/sse?api-key=' + wallet.inkey
+        )
+      }
+
+      this.pis.addEventListener('payment-received', ev =>
+        cb(JSON.parse(ev.data))
+      )
+    }
+  },
   href: {
     createWallet: function (walletName, userId) {
       window.location.href =