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.
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Co-Authored-By: Claude <noreply@anthropic.com>
- Add context support to database operations
- Implement versioned snapshots for URL history
- Update database queries to support URL timestamps
- Improve transaction handling with context
- Add utility functions for snapshot history
