feat(demo): iframe asset-rewrite proxy, AIUI mockArchy, QR 2s, dummy mints

- IndeeHub + Mempool: nginx reverse-proxy + strip X-Frame-Options/CSP + sub_filter
  rewrite of absolute asset paths so the frame-busting SPAs load in the iframe
  (mempool.space remains best-effort — third-party CSP/ws may still limit it).
- AIUI iframe gets ?mockArchy in demo → its built-in mock node data loads.
- Pay-with-mobile QR: invoice settles after ~2s (backend gate keyed by
  payment_hash) and the poll tightened to 1s, so the QR is visible before auto-pay.
- Wallet settings: dummy Cashu mints (4) + Fedimint federations (2, 222,500 sats),
  interactive per session (streaming.list/configure-mints, wallet.fedimint-list/
  join/balance).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

neode-ui/src/views/PeerFiles.vue

@@ -1304,7 +1304,7 @@ async function payWithLightning() {
 
 function scheduleInvoicePoll() {
   if (invoicePollTimer) clearTimeout(invoicePollTimer)
-  invoicePollTimer = setTimeout(pollInvoice, 3000)
+  invoicePollTimer = setTimeout(pollInvoice, 1000)
 }
 
 async function pollInvoice() {