docs: publish strategy entrypoint release line

[Pigbibi]

Summary

• document the manifest plus entrypoint boundary for live profiles
• bump UsEquityStrategies to v0.7.0 and pin QuantPlatformKit to the fixed v0.7.0 tag
• keep platform-facing integration guidance in the strategy-layer readme

Test Plan

• python3 - <<'PY'
  import tomllib
  data = tomllib.loads(open('pyproject.toml', 'rb').read().decode())
  assert data['project']['version'] == '0.7.0'
  assert any('@v0.7.0' in dep for dep in data['project']['dependencies'])
  PY
• git diff --check