The MCP reference memory server took ten correctness fixes, including a write race that discarded mutations.

Ten fix(memory) PRs merged into modelcontextprotocol/servers on September 2-3. #4555 adds an in-process async mutex because all six mutation methods independently did load-mutate-save with no synchronization, so two tool calls from a single LLM turn read the same state and the last write silently discarded the other's changes. #4738 stops the three delete methods returning a hardcoded success: true regardless of what matched, meaning an agent that deleted a misspelled name was told its memory was clean. #4717 validates entries against schema on load after a legacy memory.jsonl entry crashed search_nodes.