- Add WaitGroup synchronization for workers to prevent overlapping scheduler runs
- Increase history fetch multiplier and sleep intervals for better resource usage
- Simplify error handling and logging in worker processing
- Update SQL query to exclude error snapshots from history selection
- Fix worker ID variable reference in spawning loop
- Streamline snapshot update logic and error reporting
Add last_crawled timestamp tracking to fix fetchSnapshotsFromHistory()
infinite loop when SkipIdenticalContent=true. Now tracks actual crawl
attempts separately from content changes via database DEFAULT timestamps.