feat: add OAuth login and MCP session connect

client/client.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"encoding/json"
 	"net/http"
+
+	mcp "github.com/modelcontextprotocol/go-sdk/mcp"
 )
 
 // Client is a Robinhood Agentic MCP client.
@@ -11,7 +13,7 @@ type Client struct {
 	URL, Token, Name, Version string
 	HTTP                      *http.Client
 	Hook                      Caller
-	session                   any
+	session                   *mcp.ClientSession
 }
 
 // Call invokes an MCP tool by name and returns its JSON result.
@@ -19,5 +21,8 @@ func (c *Client) Call(ctx context.Context, name string, args map[string]any) (js
 	if c.Hook != nil {
 		return c.Hook.Call(ctx, name, args)
 	}
+	if c.session != nil {
+		return c.sessionCall(ctx, name, args)
+	}
 	return c.rpcCall(ctx, name, args)
 }