refactor cli config and move most of it to own_assist_common so that it can be reused in other clients.

own_mcp/src/mcp/chat.rs

@@ -9,7 +9,6 @@ use rmcp::ServiceError;
 use rmcp::model::{CallToolRequestParams, CallToolResult};
 use serde::Deserialize;
 use std::collections::HashMap;
-use std::fmt::Formatter;
 use thiserror::Error;
 
 #[derive(Debug, Copy, Clone, Default, Deserialize, PartialEq)]