fix: Upgrade Hugging Face Inference API to support Inference Providers (#5454)

- Upgrade @huggingface/inference from v2.6.1 to v4.13.2
- Update ChatHuggingFace to use InferenceClient with chatCompletion API
- Update HuggingFaceInference (LLM) to use v4 HfInference with Inference Providers
- Update HuggingFaceInferenceEmbedding to use v4 HfInference
- Add endpoint handling logic to ignore custom endpoints for provider-based models
- Add improved error handling and validation for API keys
- Update UI descriptions to guide users on proper configuration

Fixes #5161

Co-authored-by: Henry <hzj94@hotmail.com>

packages/components/nodes/embeddings/HuggingFaceInferenceEmbedding/core.ts

@@ -23,24 +23,22 @@ export class HuggingFaceInferenceEmbeddings extends Embeddings implements Huggin
         this.model = fields?.model ?? 'sentence-transformers/distilbert-base-nli-mean-tokens'
         this.apiKey = fields?.apiKey ?? getEnvironmentVariable('HUGGINGFACEHUB_API_KEY')
         this.endpoint = fields?.endpoint ?? ''
-        this.client = new HfInference(this.apiKey)
-        if (this.endpoint) this.client.endpoint(this.endpoint)
+        const hf = new HfInference(this.apiKey)
+        // v4 uses Inference Providers by default; only override if custom endpoint provided
+        this.client = this.endpoint ? hf.endpoint(this.endpoint) : hf
     }
 
     async _embed(texts: string[]): Promise<number[][]> {
         // replace newlines, which can negatively affect performance.
         const clean = texts.map((text) => text.replace(/\n/g, ' '))
-        const hf = new HfInference(this.apiKey)
         const obj: any = {
             inputs: clean
         }
-        if (this.endpoint) {
-            hf.endpoint(this.endpoint)
-        } else {
+        if (!this.endpoint) {
             obj.model = this.model
         }
 
-        const res = await this.caller.callWithOptions({}, hf.featureExtraction.bind(hf), obj)
+        const res = await this.caller.callWithOptions({}, this.client.featureExtraction.bind(this.client), obj)
         return res as number[][]
     }