Net Loss Per Share Attributable to Common Stockholders - Narrative (Q2) (Details) - shares |
6 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||||
| Antidilutive shares (in shares) | 76,110,000 | 267,514,000 | 236,542,000 | 234,798,000 | 141,285,000 |
| Performance Shares | |||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||||
| Antidilutive shares (in shares) | 5,248,300 | 15,454,720 | 0 | 0 | |