Why mem0, Graphiti and Cognee don't quite solve shared decision memory for Claude Code

You are three months into a codebase with Claude Code. You ask it to add search. It suggests Elasticsearch. Your team evaluated Elasticsearch in the spring, rejected it on cost, and moved on. Nothing in the repo says so, the person who made that call is on another team now, and the agent has no way to know. So you relitigate it, again. This is the part of AI-assisted development that nobody's tooling is quite solving. The agent writes code fluently. What it cannot do is remember why your code…