History / Developer Guide: Service to Service Integration

docs: add Developer-Guide:-Service-to-Service-Integration.md (SAT exchange recipe for My Apps) Documents the two-step runner refresh token -> PAT -> SAT exchange flow for My Apps calling OSC catalog services. Includes Node.js and Python examples with token caching patterns. Resolves osaas-ai#1595. Co-Authored-By: Claude <noreply@anthropic.com>

Claude Agent committed Aug 17, 2026