Fee rates from live explorer + reconnect half-open socket on wake

- Fee rates on the electrum backend came from Fulcrum's estimatefee
  (Core's estimatesmartfee): historical, laggy, floored at 1 sat/vB, so
  it showed 1 across the board while mempool.space showed 11/10. Pull the
  configured explorer's live recommendation instead (/v1/fees/recommended,
  then /fee-estimates), falling back to estimatefee only when the explorer
  is unreachable — self-hosted/regtest behaviour unchanged.
- On mobile a backgrounded page leaves the socket half-open: TCP is dead
  but readyState still reads OPEN, so wake() never reconnected and fired
  scan RPCs into the void, waiting ~20s for the heartbeat to recover.
  wake() now forces a reconnect when the socket has been silent past the
  heartbeat window, so a payment shows the instant you refocus.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/api.js b/src/api.js
index 76852d4..4a7dd75 100644
--- a/src/api.js
+++ b/src/api.js
@@ -593,7 +593,7 @@ export class Api {
 
 // Esplora /fee-estimates is { blockTarget: sat/vB }. Map to the named tiers the
 // UI expects. Round up so we never underpay.
-function mapEsploraFees(est) {
+export function mapEsploraFees(est) {
   const at = (n, d) => Math.max(1, Math.ceil(est[n] || d));
   return {
     fastestFee: at(1, 10),