Add tree_directory() and cat_multiple_files() tools

[paulmaunders]

This PR introduces two new functions to enhance the Claude Engineer script's capabilities:

1. tree_directory function:

   • Displays file and directory structure as a tree
   • Allows exclusion of specified folders at any depth (e.g. large folders like node_modules)
   • Provides a summary of total and displayed items

2. cat_multiple_files function:

   • Enables viewing contents of multiple files simultaneously
   • Implements file size limits to manage token usage efficiently

These additions improve Claude Engineer's ability to analyse project structures and review code, while optimising token usage for large codebases.

[paulmaunders]

The system prompt additions included here are a little verbose at the moment, and can probably be implemented more efficiently, however I think the general idea of giving Claude Engineer the ability to view the file structure of a project as a tree, and to also review more than one file simultaneously is worth adding!

[lgiavedoni]

+1