it doesn't seem to support 1bit

```
🥲 Failed to load the model

Failed to load model.

Error when loading model: ValueError: [quantize] The requested number of bits 1 is not supported. The supported bits are 2, 3, 4, 5, 6 and 8.
```

Start by tracing the quantization path identified as [quantize] in the loading error and find where the supported bit values are defined. Check how 1-bit models are represented and loaded, then verify the reported model loads successfully with 1-bit quantization without regressing the existing supported bit sizes.

Written by the indexing model from the issue text.