Add a tool_load tool that writes a tool name to the session's 9P tools file via ollie-9p, enabling on-demand tool loading. Reduce autoLoad lists in default.json and theo.json to bare essentials — everything else is loaded via tool_load.
These two are built-in tools always available regardless of autoload. No need to explicitly load them.
These are project data files, not community contributions. contrib/elisp stays as-is.