* refactor(chat): enhance scroll management
Add bottom detection with epsilon tolerance for precise positioning
Introduce pending anchor restoration for seamless session switching
Include active turn anchor and spacer height in message store
- Add bottom detection with epsilon tolerance for precise positioning
- Introduce pending anchor restoration for seamless session switching
Include active turn anchor and spacer height in message store
Update all import statements to use @opencode-ai/sdk/v2
Modify Vite configurations to alias new SDK path
Update API client method signatures for SDK v2 compatibility