HuggingFace Provider: Embeddings

[Kamilbenkirane]

Sub-issue of #148

Scope

Add embeddings via HuggingFace's hf-inference feature-extraction endpoint.

• Endpoint: POST https://router.huggingface.co/hf-inference/models/{model_id}/pipeline/feature-extraction
• Request: {"inputs": "text"}
• Response: JSON [[float, ...]]
• Auth: Authorization: Bearer hf_XXX via HF_TOKEN
• Streaming: Not supported

Files

Create: src/celeste/modalities/embeddings/providers/huggingface/
Modify: src/celeste/modalities/embeddings/providers/__init__.py, src/celeste/modalities/embeddings/models.py

Shares the HuggingFaceInferenceClient mixin created in the Image Generation sub-issue.