* fix(config): Add support for MCP server configuration parameters
* refact: rename the sse_readtimeout to sse_read_timeout
* update the code with review comments
* update the MCP document for the latest change
This pull request adds support for custom HTTP headers to the MCP server configuration and ensures that these headers are properly validated and included when adding new MCP servers. The changes are primarily focused on extending the schema and data handling for MCP server metadata.