Liu An 2a11b2c331 Docs: Update default chunk_token_num to 512 in API references (#8766)
### What problem does this PR solve?

Changed the default value of `chunk_token_num` from 128 to 512 in both
HTTP and Python API reference documentation to reflect the updated
configuration.

#8753

### Type of change

- [x] Documentation Update
2025-07-10 09:53:20 +08:00
..