fix(components/weaviate): fix metadata special chars upsertion failure (#4436)

* Enhancement: Add recursive key normalization for metadata in Weaviate vector store

- Introduced `normalizeKeysRecursively` utility to standardize metadata keys.
- Updated Weaviate vector store to apply normalization on document metadata before processing.

* format(compnonents/utils): format for ci

* Update utils.ts

---------

Co-authored-by: Henry Heng <henryheng@flowiseai.com>

packages/components/nodes/vectorstores/Weaviate/Weaviate.ts

@@ -4,7 +4,7 @@ import { WeaviateLibArgs, WeaviateStore } from '@langchain/weaviate'
 import { Document } from '@langchain/core/documents'
 import { Embeddings } from '@langchain/core/embeddings'
 import { ICommonObject, INode, INodeData, INodeOutputsValue, INodeParams, IndexingResult } from '../../../src/Interface'
-import { getBaseClasses, getCredentialData, getCredentialParam } from '../../../src/utils'
+import { getBaseClasses, getCredentialData, getCredentialParam, normalizeKeysRecursively } from '../../../src/utils'
 import { addMMRInputParams, resolveVectorStoreOrRetriever } from '../VectorStoreUtils'
 import { index } from '../../../src/indexing'
 import { VectorStore } from '@langchain/core/vectorstores'
@@ -175,7 +175,11 @@ class Weaviate_VectorStores implements INode {
             const finalDocs = []
             for (let i = 0; i < flattenDocs.length; i += 1) {
                 if (flattenDocs[i] && flattenDocs[i].pageContent) {
-                    finalDocs.push(new Document(flattenDocs[i]))
+                    const doc = { ...flattenDocs[i] }
+                    if (doc.metadata) {
+                        doc.metadata = normalizeKeysRecursively(doc.metadata)
+                    }
+                    finalDocs.push(new Document(doc))
                 }
             }