Correct Levels 4/5 admission labels: Level 5 is admitted and difficulty-matched in all five domains; Level 4 is confirmed in four of five (mathir is not difficulty-matched). The published labels had been copied from each frozen dataset identity, which is not revised after confirmation. No data file is changed.

Add Levels 4 and 5 (10 configs, 6400 rows), labelled pending held-out confirmation

Release frozen ModeBench Levels 1, 2 and 3 with verified splits and executable evaluation

initial commit