Fix CLI crash when a remote MCP server is offline but enabled (#13639)

Remote (SSE/streamable HTTP) MCP connects run on the session.create
critical path, which the hub caps at 30s. Without a connect budget an
unreachable server spent the full 60s default request timeout (with the
SSE transport stuck in a reconnect loop), stalling session.create past
the hub deadline and tearing the whole session down - the interactive
TUI exited and one-shot runs failed. Stdio servers already have a
bounded initialize budget for exactly this reason; give URL clients the
same treatment with a 10s default connect budget that an explicit
timeout overrides in either direction.

Fixes #13597

Co-authored-by: Saoud Rizwan <saoudrizwan@users.noreply.github.com>