Stock-based compensation - Compensation Expense Recognized Under 2024 Plan (Details) - Equity Incentive Plan 2024 [Member] - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Stock-based compensation [Abstract]
Compensation expense	$ 197	$ 206	$ 302	$ 508
Location, Statement of Income, Balance [Axis]: us-gaap:GeneralAndAdministrativeExpense
Stock-based compensation [Abstract]
Compensation expense	147	148	221	381
Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense
Stock-based compensation [Abstract]
Compensation expense	$ 50	$ 58	$ 81	$ 127

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details