fix: chunk_overlap=100 per assignment spec

vector_store.py

@@ -53,7 +53,7 @@ def get_vector_store() -> QdrantVectorStore:
 def chunk_document(content: str, title: str) -> list[Document]:
     splitter = RecursiveCharacterTextSplitter(
         chunk_size=500,
-        chunk_overlap=50,
+        chunk_overlap=100,
     )
     documents = splitter.create_documents(
         texts=[content],