Integrate BACKBEAT SDK and resolve KACHING license validation

Major integrations and fixes:
- Added BACKBEAT SDK integration for P2P operation timing
- Implemented beat-aware status tracking for distributed operations
- Added Docker secrets support for secure license management
- Resolved KACHING license validation via HTTPS/TLS
- Updated docker-compose configuration for clean stack deployment
- Disabled rollback policies to prevent deployment failures
- Added license credential storage (CHORUS-DEV-MULTI-001)

Technical improvements:
- BACKBEAT P2P operation tracking with phase management
- Enhanced configuration system with file-based secrets
- Improved error handling for license validation
- Clean separation of KACHING and CHORUS deployment stacks

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

vendor/github.com/blevesearch/upsidedown_store_api/README.md

@@ -0,0 +1,7 @@
+# Upsidedown Store API
+
+Upsidedown supports a pluggable Key/Value storage interface.
+
+By placing these interfaces in their own, *hopefully* slowly evolving module, it frees up Upsidedown and the underlying storage implementations to each introduce new major versions without interfering with one another.
+
+With that in mind, we anticipate introducing non-breaking changes only to this module, and keeping the major version at 1.x for some time.