DEVELOPER_GUIDE still says the HTTP MCP server does not emit unsolicited server-to-client frames, but current USER_GUIDE/runtime behavior documents opt-in keep-alive notifications via CDIDX_MCP_KEEP_ALIVE_INTERVAL_S. Align the developer guide wording with the current keep-alive contract.
DEVELOPER_GUIDE still says the HTTP MCP server does not emit unsolicited server-to-client frames, but current USER_GUIDE/runtime behavior documents opt-in keep-alive notifications via CDIDX_MCP_KEEP_ALIVE_INTERVAL_S. Align the developer guide wording with the current keep-alive contract.