Convy MCP beta

Read tools: convy_get_context, convy_get_shopping_context, convy_get_shopping_list, convy_get_task_list, convy_get_recent_activity.
Limited write tools: convy_add_shopping_items, convy_update_shopping_items_status, convy_add_tasks, convy_update_tasks_status.
Scopes: convy.households.read, convy.lists.read, convy.items.read, convy.tasks.read, convy.activity.read, convy.items.write, convy.tasks.write.