Add config settings for generating shortcut tools

[dvcrn]

• Add a config env var flag to toggle generation of shortcut tools (eg GENERATE_SHORTCUT_TOOLS) which by default is set to true
• Add a config env var flag to toggle generation of shortcut names into the run_shortcut tool description (eg INJECT_SHORTCUT_LIST). When set to true, the list of available shortcuts with their identifier is instead inserted into the tool description for run_shortcut to teach the LLM which shortcuts are available

Maybe related #4