bug:auth flows like sign in, sign out and account center Flash bang the user (Theme Flash)

### Describe the bug Love logto, amazing product. One thing is becoming a big issue in prod though. Theme Flashing. Auth flows like sign in and sign out and especially visiting the account center flash bang the user quite significantly. It's to the point where I'm experiencing significant eye strain during testing. Logto OSS: v1.39.0 next: 15.5.9 @logto/next: ^4.2.9 ### Expected behavior Logto should pick up on my theme preferences and render with the correct theme on initial page load. ### How to reproduce? Trigger a sign in, sign out and navigate to the account center (/account/security) from a next.js app or any other app. I doubt this is a Next.js specific issue ### Environment Self-hosted (Docker image) ### Screenshots Here is a video demo of the issue: ⚠️ WARNING: FLASHING LIGHTS / PHOTOSENSITIVITY https://github.com/user-attachments/assets/5216ea15-5f3a-4aa8-9427-9c15f18502ed