Local-first AI memory built to forget.  Depth-axis architecture
with verifiable purge receipts.  ForgetEval methodology proposal.

  - LongMemEval-S: 97.4% R@5 (vs MemPalace 96.6%)
  - ForgetEval (1000 cases): 99.3%
  - Local-first SQLite + MCP-ready + Ed25519 purge receipts