hadb-io

Shared S3/retry/upload infrastructure for the hadb ecosystem.

• Retry — RetryPolicy with exponential backoff, full jitter, CircuitBreaker, error classification
• S3 — Client helpers, upload/download, checksums (feature-gated behind s3)
• ObjectStore — Rich storage trait for bulk replication data + S3Backend impl
• ConcurrentUploader — Bounded-concurrency upload framework with shutdown drain
• Webhook — HTTP POST notifications with HMAC-SHA256 signing, event filtering
• Retention — GFS (Grandfather/Father/Son) snapshot rotation
• Config — S3Config, WebhookConfig, CacheConfig, duration string parsing

use hadb_io::{RetryPolicy, S3Backend, ObjectStore, WebhookSender};

// Your Replicator implementation uses these instead of
// writing S3 upload/retry logic from scratch.