fix(demo): iframe mempool+indeehub directly, serve real UIs statically, AIUI canned

- Mempool and IndeeHub load their real site directly in the iframe (reverted the
  proxy/new-tab — per request "use https://indee.tx1138.com/").
- Real app UIs now served as whole static dirs under /app/<id>/ (express.static)
  so their bundled assets (qrcode.js, css, bg images) resolve; /app/<id>/assets/*
  redirect to the frontend's shared assets. Fixes the console 404 cascade.
- Bitcoin Core/Knots: register rpc/v1 + bitcoin-rpc on their paths (relay-status
  no longer 404s); per-impl bitcoin-status preserved.
- AIUI chat returns a fixed line in demo ("Not available in demo, check out the
  previous chats to experience AIUI") instead of calling Claude — no key spend.
- Add /api/app-catalog (serves the baked catalog) to stop that 404.

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

neode-ui/vite.config.ts

@@ -161,7 +161,6 @@ export default defineConfig({
       '/electrs-status': { target: process.env.BACKEND_URL || 'http://localhost:5959', changeOrigin: true, secure: false },
       '/proxy': { target: process.env.BACKEND_URL || 'http://localhost:5959', changeOrigin: true, secure: false },
       '/lnd-connect-info': { target: process.env.BACKEND_URL || 'http://localhost:5959', changeOrigin: true, secure: false },
-      '/app/indeedhub': { target: 'https://indee.tx1138.com', changeOrigin: true, secure: false, rewrite: (p: string) => p.replace(/^\/app\/indeedhub/, '') },
       // Serve the node's deployed AIUI same-origin like production (set VITE_AIUI_URL=/aiui/)
       '/aiui': {
         target: process.env.AIUI_PROXY_TARGET || 'http://127.0.0.1:80',