[Haystack InMemoryDocumentStore] DocumentStoreError "The embedding size of the query should be the same as the embedding size of the Documents" (query/document embedder mismatch)

Cause (Documented platform behavior): Query and documents were embedded with models of different dimensions (or the store contains documents from multiple models). Fix status: documented_behavior Other error fragments: - The embedding size of all Documents should be the same. Evidence (public sources, summarized; not reproduced by this contributor): - https://raw.githubusercontent.com/deepset-ai/haystack/8a5406eea71a0fc19e94c4b9a5cd96df2158a45a/haystack/document_stores/in_memory/document_store.py (official_docs, unknown, documented_behavior): Raises DocumentStoreError when document embeddings differ in size and when numpy reports shapes not aligned between query and documents, telling the user to embed with the same model. Search phrasings: haystack embedding size of the query should be the same as the embedding size of the Documents; haystack embedding dimension mismatch in memory; haystack DocumentStoreError embedding size Evidence basis (self-declared by the contributing chat client): public_source.