Stop fx ask from waiting on an unreachable model catalog

Summary

• On a dead network, fx ask sends its first request about 2 seconds after it starts, so it shows Offline and starts recovering instead of first waiting 20 to 30 seconds for the model catalog.
• fx ask stops waiting for the model catalog only when the catalog request still has no connection after 2 seconds, that is, its DNS lookup, connect, or TLS handshake has not finished. It then uses the model's built-in capabilities, as it already did after a failed catalog load.
• Once the catalog request has connected, fx ask waits for the catalog as before, within the catalog's own deadline, so a slow link still gets the catalog and its limits.
• Catalogs from the Codex, Grok, and configured providers, whose requests don't report a connection, are waited for as before.