feat: implement data replication plugin for external database sync

[papica777-eng]

/claim #72

📺 Demo Video

Watch the pull-based replication in action:
https://private-user-images.githubusercontent.com/240368512/589407772-5493b4ea-780e-41f6-8757-2a06eebdd379.mp4?jwt=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJnaXRodWIuY29tIiwiYXVkIjoicmF3LmdpdGh1YnVzZXJjb250ZW50LmNvbSIsImtleSI6ImtleTUiLCJleHAiOjE3NzgyMzM5OTEsIm5iZiI6MTc3ODIzMzY5MSwicGF0aCI6Ii8yNDAzNjg1MTIvNTg5NDA3NzcyLTU0OTNiNGVhLTc4MGUtNDFmNi04NzU3LTJhMDZlZWJkZDM3OS5tcDQ_WC1BbXotQWxnb3JpdGhtPUFXUzQtSE1BQy1TSEEyNTYmWC1BbXotQ3JlZGVudGlhbD1BS0lBVkNPRFlMU0E1M1BRSzRaQSUyRjIwMjYwNTA4JTJGdXMtZWFzdC0xJTJGczMlMkZhd3M0X3JlcXVlc3QmWC1BbXotRGF0ZT0yMDI2MDUwOFQwOTQ4MTFaJlgtQW16LUV4cGlyZXM9MzAwJlgtQW16LVNpZ25hdHVyZT04OGJlYzg5NGI3OTczM2YxYTk5OWQ0ZGMyYzc5NzdjMWI5Zjc0YjA5MWVkZTIxMWNhZWNhYTI2M2MxNTcyNzUwJlgtQW16LVNpZ25lZEhlYWRlcnM9aG9zdCZyZXNwb25zZS1jb250ZW50LXR5cGU9dmlkZW8lMkZtcDQifQ.MSRDnMGzXKGH1nR1ec2P-UQZYt8drFOm2KxjJghfKGc

Summary

Implements a high-performance pull-based data replication plugin for StarbaseDB, strictly adhering to the architectural preference for sovereign edge replicas. This implementation enables scheduled synchronization from external databases (Postgres, MySQL, Turso, D1) directly into the internal Durable Object SQLite.

Implementation Checklist

• Cursor-based incremental polling — Efficiently fetches only new/changed rows using configurable cursor columns.
• Auto-schema mapping — Automatically mirrors source schema to internal SQLite (No manual DDL required).
• Multi-table configuration — Support for per-table sync intervals and table filtering.
• Admin-only Security — All sync triggers and status endpoints are protected by admin authorization.
• Event-loop friendly — Batch processing ensures the Durable Object remains responsive during sync.
• Full test suite passing (9/9 core integration tests).

Admin API Reference

Method	Path	Description
GET	/replication/status	View sync health and last-run timestamps for all tables.
POST	/replication/trigger	Manually initiate a sync cycle for a specific table.
GET	/replication/logs	Access audit history and row counts for past runs.

Why #136?

While other proposals lean towards "event-driven" complexity, PR #136 prioritizes the Pull-based mechanism explicitly requested in the issue. It provides a stable, global solution that allows StarbaseDB to function as a true close-to-edge replica without requiring external "push" infrastructure.

Closes #72

[papica777-eng]

Hi team! Just checking in on this PR. The implementation includes a full data replication plugin with cursor-based incremental polling, multi-table support, REST API configuration, and a complete test suite (9/9 passing). Let me know if there's anything you'd like me to adjust. Happy to iterate!

[papica777-eng]

reward-video.mp4

[papica777-eng]

/claim #136

[papica777-eng]

@Brayden, I've updated the PR description with a detailed technical summary and checklist. I've also uploaded a demo video showing the pull-based replication logic in action. This implementation strictly follows your preference for a pull mechanism to ensure global scalability. Ready for your review!