The reranker examples configured a `reranker` block but called
memory.search(...) without rerank=True. Memory.search() defaults rerank=False
(mem0/memory/main.py:1333) and only reranks 'if rerank and self.reranker'
(:1447), so reranking never ran:
- cohere, zero_entropy, llm, sentence_transformer print result['rerank_score'],
which doesn't exist unless reranking runs -> KeyError on copy-paste.
- optimization (reranker benchmark) and custom-prompts (reranker-prompt test)
silently measured un-reranked search.
Add the missing rerank=True flag to every search meant to exercise the reranker.
kartik-mem0