FAIR VALUE MEASUREMENTS - Schedule Of Aggregate Fair Value Of Warrants (Details) - Level 3 [Member] - Common Stock Warrant [Member]	6 Months Ended		12 Months Ended
	Jun. 30, 2025 $ / shares	Jun. 30, 2024 $ / shares	Dec. 31, 2024 $ / shares	Dec. 31, 2023 $ / shares	Jun. 30, 2025 £ / shares
Junior Note Warrants [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock price	$ 0.35
Expected volatility				66.30%
Risk-free interest rate	3.70%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Junior Note Warrants [Member] \| Minimum [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock price		$ 0.03	$ 0.03	$ 0.15
Expected term (in years)	3 years 4 months 24 days	4 years 4 months 24 days	3 years 10 months 24 days	4 years 10 months 24 days
Expected volatility	66.20%	58.90%	58.90%
Risk-free interest rate		4.20%	3.60%	3.80%
Junior Note Warrants [Member] \| Maximum [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock price		$ 0.14	$ 0.67	$ 0.18
Expected term (in years)	4 years 1 month 6 days	4 years 8 months 12 days	4 years 10 months 24 days	5 years
Expected volatility	70.80%	69.80%	79.60%
Risk-free interest rate		4.30%	4.30%	4.10%
August 2024 Convertible Note Derivative Liability [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Expected dividend yield			0.00%
August 2024 Convertible Note Derivative Liability [Member] \| Minimum [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock price			$ 0.51
Expected term (in years)			4 months 6 days
Expected volatility			253.00%
Risk-free interest rate			4.60%
August 2024 Convertible Note Derivative Liability [Member] \| Maximum [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock price			$ 1.82
Expected term (in years)			5 months 15 days
Expected volatility			285.40%
Risk-free interest rate			5.00%
Convertible Notes Receivable [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Expected dividend yield	0.00%
Convertible Notes Receivable [Member] \| Minimum [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock price \| £ / shares					£ 0.000038
Expected term (in years)	1 year
Expected volatility	157.70%
Risk-free interest rate	3.80%
Convertible Notes Receivable [Member] \| Maximum [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock price \| £ / shares					£ 0.000048
Expected term (in years)	1 year 3 months
Expected volatility	188.10%
Risk-free interest rate	4.20%