Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($)	3 Months Ended								12 Months Ended
	Sep. 28, 2024	Jun. 29, 2024	Mar. 30, 2024	Dec. 30, 2023	Sep. 30, 2023	Jun. 24, 2023	Mar. 25, 2023	Dec. 24, 2022	Sep. 28, 2024	Sep. 30, 2023	Sep. 24, 2022
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Loss before income tax									$ (80,460,000)	$ (212,514,000)	$ (139,089,000)
Tax on pre-tax loss									(16,860,000)	(44,628,000)	(29,209,000)
Loss not subject to tax									14,175,000	39,497,000	27,767,000
State income tax rate									(2,051,000)	(3,363,000)	(744,000)
Permanent differences									769,000	992,000	46,000
Adjustment for foreign income tax rate differential									45,000	241,000	1,346,000
Credits									(2,763,000)	(1,218,000)	(374,000)
Valuation allowance									(5,341,000)	3,187,000	1,168,000
Impact on foreign activity									(398,000)	575,000	0
Return to provision									5,000	88,000	0
Adjustment for rate changes									16,620,000	0	0
Other									11,000	9,000	0
Total income tax	$ 4,110,000	$ 182,000	$ (252,000)	$ 172,000	$ (4,859,000)	$ 5,000	$ (17,000)	$ 251,000	$ 4,212,000	$ (4,620,000)	$ 0
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Tax on pre-tax loss									21.00%	21.00%	21.00%
Loss not subject to tax									(18.00%)	(19.00%)	(20.00%)
State income tax rate									3.00%	2.00%	1.00%
Permanent differences									(1.00%)	0.00%	0.00%
Adjustment for foreign income tax rate differential									0.00%	0.00%	(1.00%)
Credits									3.00%	1.00%	0.00%
Valuation allowance									7.00%	(1.00%)	(1.00%)
Impact on foreign activity									0.00%	0.00%	0.00%
Return to provision									0.00%	0.00%	0.00%
Adjustment for rate changes									(21.00%)	0.00%	0.00%
Other									0.00%	0.00%	0.00%
Total income tax									(5.00%)	2.00%	0.00%