Accounts receivable, net - Accrued Defective Return and Discount Accounts Roll Forward (Details) - USD ($) |
3 Months Ended | 6 Months Ended | |
|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Accounts Receivable, Accrued Defective Return and Discount, Current [Roll Forward] | |||
| Beginning balance | $ 1,007,319 | $ 1,001,927 | |
| Provision | $ 51,900 | 488,492 | 51,900 |
| Ending balance | $ 1,053,827 | $ 1,495,811 | $ 1,053,827 |