A Lightning payment that can't be covered says why, not 'Payment failed'

A user renewed all ten of their coins (55,611 sats) from the coins page,
tried to pay a 55,300-sat invoice three minutes later, and was told only
'Payment failed'. Nothing had failed: the renewal's round ran at once,
but its coins stay unspendable until the round's transaction confirms
on-chain, and that block took 64 minutes. The quote found no spendable
coin and gave up with the generic message; nothing reached the server.

- The quote now tells apart (lnShortfall): money held by another payment
  (wait, as before — now by sum, not one coin covering it all), money a
  renewal holds ('Nothing was sent. N sats are being renewed…'), and a
  real shortfall ('needs X sats with its fee, Y available'). Coins leaving
  in an offboard or exit are never waited for.
- The manager's 'insufficient ark balance' names a renewal too.
- The coins page says before the tap that renewed coins can't be spent
  until the round confirms, and that renewing every coin leaves nothing
  to pay with meanwhile.

tools/ark/ln-shortfall-test.js

Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01ULQZS9MQa6iAsXnrJUD9Du

1 files changed, 6 insertions, 2 deletions

diff --git a/src/ark/manager.js b/src/ark/manager.js
index dc80ca3..a114702 100644
--- a/src/ark/manager.js
+++ b/src/ark/manager.js
@@ -33,6 +33,7 @@ import {
   requestLightningPayHtlcRevocation, startLightningReceive, checkLightningReceive,
   prepareLightningReceiveClaim, claimLightningReceive, cancelLightningReceive,
   lightningReceiveAttestation,
+  lnShortfall,
 } from './lightning.js';
 import {
   boardFee, p2trAddress, buildBoard, requestBoardCosign,
@@ -868,8 +869,11 @@ export class ArkManager {
     const expiredSat = this.state.vtxos
       .filter((v) => v.state === 'spendable' && this._expired(v, tip))
       .reduce((n, v) => n + v.amountSat, 0);
-    return expiredSat
-      ? `insufficient ark balance (${expiredSat} sat expired and unusable)`
+    if (expiredSat) return `insufficient ark balance (${expiredSat} sat expired and unusable)`;
+    // coins a renewal took stay unspendable until its round confirms on-chain
+    const renewing = lnShortfall(this.state.vtxos, this.state.actions, Infinity).renewingSat;
+    return renewing
+      ? `insufficient ark balance (${renewing} sat are being renewed and can't be spent until the renewal confirms on-chain)`
       : 'insufficient ark balance';
   }