Show HN: Maat – AI agents that can diagnose Ubuntu but can't change it

Maat is an open-source MCP server and toolkit that lets AI agents diagnose Ubuntu systems from inside a strictly confined snap with read-only interfaces and no network access, proposing fixes as typed plans that a user approves via polkit before execution. It includes maatctl for reviewing and applying plans, a hash-chained audit trail with journal checkpoints, and maat-bench, an open benchmark of deliberately broken Ubuntu machines. The project is a developer preview implemented in Go, with first results from two small local models reported as a preliminary data point rather than a ranking.