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/Chat.vue

@@ -62,6 +62,7 @@ import { ref, computed, onMounted, onBeforeUnmount } from 'vue'
 import { useRouter } from 'vue-router'
 import { useI18n } from 'vue-i18n'
 import { ContextBroker } from '@/services/contextBroker'
+import { IS_DEMO } from '@/composables/useDemoIntro'
 
 const { t } = useI18n()
 
@@ -71,9 +72,12 @@ const aiuiConnected = ref(false)
 let broker: ContextBroker | null = null
 
 const aiuiUrl = computed(() => {
+  // Demo: ?mockArchy makes AIUI use its built-in mock node data (apps, system,
+  // network, wallet, bitcoin, files) and &seed pre-loads the example chats.
+  const demo = IS_DEMO ? '&mockArchy=1&seed=1' : ''
   const envUrl = import.meta.env.VITE_AIUI_URL
-  if (envUrl) return `${envUrl}?embedded=true&hideClose=true`
-  if (import.meta.env.PROD) return '/aiui/?embedded=true&hideClose=true'
+  if (envUrl) return `${envUrl}?embedded=true&hideClose=true${demo}`
+  if (import.meta.env.PROD || IS_DEMO) return `/aiui/?embedded=true&hideClose=true${demo}`
   return ''
 })