Liu An 2ff911b08c
Fix: Set default rerank_model to empty string in Chat class (#8130)
### What problem does this PR solve?

Previously when LLM.rerank_model was not configured:
- SDK would pass None as the value
- Database field with null=False constraint would reject it
- Caused storage failures for unset rerank_model cases

Now:
- SDK checks for None value before database operations
- Provides empty string as default when rerank_model is unset

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
2025-06-09 11:43:42 +08:00
..
2025-01-21 20:52:28 +08:00