Bitcoin UI and Electrs UI proxy API calls to 127.0.0.1 services
(Bitcoin RPC on 8332, backend on 5678). With port-mapped containers,
127.0.0.1 is the container's own localhost — the proxy fails and UIs
show "Unable to connect to Bitcoin node".
Fix: bitcoin-ui and electrs-ui use --network host (internal ports
8334 and 50002 don't conflict with host nginx on 80/443). LND UI
stays port-mapped (-p 8081:80) because port 80 would conflict.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>