Electrum WSS test endpoint down (electrumx-server.test.tbtc.network) causing integration skips

[piotr-roslaniec]

Problem
The Electrum WSS endpoint used in tests (wss://electrumx-server.test.tbtc.network:8443) is offline. CI shows TLS handshake failures; current behavior is Cloudflare 522 (and previously sslv3 alert handshake failure with no peer cert).

Impact

• All electrumx wss integration cases in pkg/bitcoin/electrum/electrum_integration_test.go are skipped to keep CI green.
• Coverage gap for WSS-specific Electrum behavior.

Evidence / Repro

• Run openssl s_client -connect electrumx-server.test.tbtc.network:8443 -servername electrumx-server.test.tbtc.network → handshake fails (no cert).
• Curl today: curl -I https://electrumx-server.test.tbtc.network:8443/ → HTTP 522.
• CI run: https://github.com/threshold-network/keep-core/actions/runs/19791850413 (client-integration-test).

Expected

• WSS host is reachable with a valid cert and Electrum protocol responses.

Actual

• Endpoint unreachable / TLS handshake failure → integration tests cannot run.

Requested actions

• Restore or replace the test WSS endpoint.
• Provide new URL/cert details.
• Remove test skip once a healthy endpoint is available.