Add deployment artifact integrity check

Dockerfile

@@ -36,6 +36,8 @@ ENV HF_HUB_OFFLINE=1 \
 
 COPY --chown=user:user src/ src/
 COPY --chown=user:user knowledge_base/ knowledge_base/
+RUN echo "451a017d1d53ef21f502a2effd9edf8932d39a55e584e6888b9e99529ea41c09  knowledge_base/indexes/medlineplus/multilingual-e5-small/embeddings.npy" \
+    | sha256sum --check
 
 EXPOSE 7860
 

src/medirag/vector_index.py

@@ -327,9 +327,14 @@ class LoadedVectorIndex:
             raise IndexValidationError(
                 "Chunk corpus hash does not match the index manifest"
             )
-        if sha256_file(self.embeddings_path) != vectors_info["npy_sha256"]:
+        observed_embeddings_sha256 = sha256_file(self.embeddings_path)
+        expected_embeddings_sha256 = str(vectors_info["npy_sha256"])
+        if observed_embeddings_sha256 != expected_embeddings_sha256:
             raise IndexValidationError(
-                "Embedding matrix hash does not match the index manifest"
+                "Embedding matrix hash does not match the index manifest "
+                f"(expected={expected_embeddings_sha256}, "
+                f"observed={observed_embeddings_sha256}, "
+                f"bytes={self.embeddings_path.stat().st_size})"
             )
 
         fingerprint_payload = _index_fingerprint_payload(