Redeemable Convertible Preferred Stock and Stockholders' Deficit - Stock-Based Compensation Expense (FY) (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | 12 Months Ended | ||||
|---|---|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
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| Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] | |||||||
| Unrecognized compensation costs, stock options | $ 73,000 | $ 73,000 | |||||
| Stock-based compensation expense | $ 145,005 | $ 7,660 | $ 328,978 | $ 15,849 | $ 31,487 | $ 15,154 | $ 1,490 |
| Stock Options | |||||||
| Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] | |||||||
| Unrecognized compensation costs, stock options | $ 91,000 | ||||||
| Unrecognized cost, recognition period | 2 years | 3 years | |||||
| Restricted Stock Units (RSUs) | |||||||
| Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] | |||||||
| Unrecognized compensation costs, stock options | $ 600,000 | ||||||
| Unrecognized cost, recognition period | 3 years | 2 years | |||||
| Stock-based compensation expense | $ 78,000 | ||||||
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- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of cost to be recognized for option under share-based payment arrangement. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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