Function fix_dir 

pub fn fix_dir(dir: &Path) -> FixOutcome

Detects fixable drift in the ARA artifact at dir, applies the safe fixes to trace/exploration_tree.yaml / logic/claims.md in place, and returns a FixOutcome. Native only.

Edits and guard validation run entirely in memory; a file is written only after its edits pass, so a rejected fix never corrupts a source file. Running fix_dir twice is a no-op the second time (idempotent).