Stockholders' equity - Schedule of equity awards (Detail) - Employee stock option [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options,Outstanding, beginning of period	1,182,140	107,993
Stock Options, Granted	3,720,000	1,076,538
Stock Options, Expired	0	(2,038)
Stock Options, Forfeited	0	(353)
Stock Options, Outstanding, end of period	4,902,140	1,182,140	107,993
Stock Options, Exercisable, end of period	858,377
Weighted-average Exercise price, beginning of period	$ 6.58	$ 31.88
Weighted-average Exercise Price, Granted	12.16	5.01
Weighted-average Exercise Price, Expired	0	501.93
Weighted-average Exercise Price, Forfeited	0	74.18
Weighted-average Exercise Price, Exercise price, end of period	10.81	$ 6.58	$ 31.88
Weighted-average Exercise Price, Exercisable, end of period	$ 10.68
Weighted-average Remaining Contractual Term, Outstanding	9 years 2 months 26 days	9 years 6 months 3 days	8 years 11 months 15 days
Weighted-average Remaining Contractual Term, Granted	9 years 5 months 19 days	9 years 7 months 28 days
Weighted-average Remaining Contractual Term, Exercisable	8 years 10 months 9 days
Aggregate Intrinsic Value, Outstanding	$ 2,342,847	$ 11,888
Aggregate Intrinsic Value, Outstanding	7,728,384	$ 2,342,847	$ 11,888
Aggregate Intrinsic Value,Exercisable	$ 2,750,369