Fair value measurements - Schedule of fair value on a recurring basis (Details) - USD ($)	Dec. 31, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents	$ 8,705,218	$ 4,164,323
Liabilities:
Debentures	5,245,543	0
Fair Value, Recurring [Member]
Current assets:
Cash and cash equivalents	8,705,218	4,164,323
Total assets measured at fair value	8,705,218	4,164,323
Fair Value, Recurring [Member] | Level 1 [Member]
Current assets:
Cash and cash equivalents	8,705,218	4,164,323
Total assets measured at fair value	8,705,218	4,164,323
Fair Value, Recurring [Member] | Level 2 [Member]
Current assets:
Cash and cash equivalents	0	0
Total assets measured at fair value	0	0
Fair Value, Recurring [Member] | Level 3 [Member]
Current assets:
Cash and cash equivalents	0	0
Total assets measured at fair value	$ 0	$ 0