No actionable issues found.

After analyzing this PR thoroughly, I find no actionable defects. The changes are:

1. Database cleanup now uses shared connection pool: The DatabaseCleanup struct now accepts Arc<PriceDatabase> in its constructor and uses self.database.get_connection() to obtain pooled connections instead of opening its own DATABASE_PATH directly. This improves resource management and concurrency handling.

2. Error logging in aggregation: The aggregate_buckets function now uses warn! to log failures when retrieving open/close prices from source buckets, falling back to avg_price instead of silently using the fallback value.

3. Unused variable cleanup: The _effective_start variable was removed from health.rs (it computed if start_time > 0 { start_time } else { now } but was never used in the actual health check logic). The DATABASE_PATH import was removed from db_cleanup.rs since it's no longer needed.

The code changes are sound and accomplish the stated objectives without introducing runtime defects.