Virtual file system tool/component

So agents can take actions on files with file version control: especially helpful for apps doing code generation.

The issue does not identify any files, tests, or entry points. Start by tracing how tools and agent actions are defined in the repository, then clarify the virtual filesystem and version-control requirements with maintainers. Done should include an agreed design and an implemented tool/component that lets agents take versioned file actions.

Written by the indexing model from the issue text.