13.0.3 — MCP Registry, security policy, honest metadata

Nothing in the runtime changed. This release exists so the package carries
the metadata the wider ecosystem reads.

Added

• server.json and an mcp-name marker in the README, so the package can be
  published to the official MCP Registry.
  The registry verifies PyPI ownership by matching that marker against the
  package description, which is why it needs a release rather than a commit.
• SECURITY.md — supported versions, private reporting through GitHub
  Security Advisories, and a threat model that says plainly what is in scope
  for a local-first server and what is not.
• CONTRIBUTING.md — development setup, the memory_core / ai_layer import
  rule that tests/test_v11_layer_separation.py enforces, and the two rules
  learned the hard way: tests must skip on absent gitignored corpora, and
  benchmark runners must pass record_usage=False.

Fixed

• The PyPI description advertised 46 tools; the server exposes 74. The
  repository description on GitHub still quoted LongMemEval R@5 97.45%,
  a number 13.0.0 retired when the runner stopped measuring its own
  self-contained retrieval stack. Both now match the README: 74 tools,
  95.1% R@5.