* feat: independent versioning for integrations
- Add per-integration changelog pages at /changelog/integrations/<name>
- Move main changelog to changelog/index.md (URL unchanged)
- Add --integration flag to generate-changelog for LLM-based per-integration changelog generation
- Add scripts/release-integration.sh <name> <version> for cutting integration releases
- Add .github/workflows/release-integration.yml to publish on integrations/** tags
- Remove integrations from main release.sh and release.yml cycle
* fix: add agno and hermes integration docs to version-0.4 for production build
* chore: apply ruff formatting to generate_changelog.py
