Loss Per Share - Schedule of Outstanding Shares of Potentially Dilutive Securities (Detail) - shares	6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from the computation of diluted net loss per share attributable to common stockholders	38,422,230	252,505,048
Common stock options outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from the computation of diluted net loss per share attributable to common stockholders	27,042,019	92,302,779
Convertible redeemable preferred stock outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from the computation of diluted net loss per share attributable to common stockholders	0	159,273,176
Unvested restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from the computation of diluted net loss per share attributable to common stockholders	239,766	929,093
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from the computation of diluted net loss per share attributable to common stockholders	728,278	0
Warrants to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from the computation of diluted net loss per share attributable to common stockholders	10,412,167	0