add optional timeout field to mcp config to allow users to use responding servers (#3558)

Co-authored-by: Matt Gillard <matt-github@gillard.biz>
Co-authored-by: opencode-agent[bot] <opencode-agent[bot]@users.noreply.github.com>
Co-authored-by: rekram1-node <rekram1-node@users.noreply.github.com>