chore: support Ruff 0.16

[stepanov1975]

Summary

• allow Ruff 0.16 in the test dependency range
• preserve Ruff's pre-0.16 default lint rules explicitly so the tooling upgrade does not introduce 108 unrelated diagnostics
• bump synchronized plugin metadata to 0.4.5 and add release notes
• update version-bearing and release-note tests

Supersedes #25, which could not pass the version-policy or Ruff gates as submitted.

Verification

• python -m pytest -q
• python -m ruff check . (Ruff 0.16.1)
• python -m mypy
• python scripts/check_version_policy.py --base-ref origin/main
• git diff --check
• focused public/plugin contract tests
• clean wheel and sdist build
• python -m twine check for both artifacts
• wheel and sdist install/entry-point smoke tests

Checklist

• Generated state (*.sqlite, *.jsonl, caches, .env) is not committed
• Plugin version bumped in plugin.yaml, pyproject.toml, and hermes_local_knowledge/__init__.py
• No install or runtime configuration behavior changed
• No security-sensitive data or paths added