[FEATURE] Change Data Capture (CDC) — stream data changes to external systems

[ElioNeto]

Description

Modern applications need to react to data changes in real-time. ApexStore has no mechanism to subscribe to data changes.

Proposed Implementation

1. Add a WAL tailer that streams changes to a configurable output
2. Support outputs: Kafka, RabbitMQ, WebSocket, gRPC stream
3. Each change event includes: key, new_value, old_value, timestamp, operation_type (put/delete)
4. Support at-least-once delivery semantics with offset tracking
5. Add CDC configuration via config.cdc section

API

apexstore-cli cdc subscribe --output kafka://localhost:9092/changes

Impact

• Enables real-time replication to other systems
• Enables event-driven architectures
• Enables cache invalidation (Redis, CDN)
• Critical for microservices ecosystems

Labels

[ElioNeto]

Fixed in commit 1d8c830.