feat: Comparison history/library

[ikorich]

Summary

Save and browse previous comparisons for reuse.

Motivation

Users often create similar comparisons - history allows quick access.

Implementation

• Save comparisons with metadata
• Browse history in side panel
• Load previous comparison
• Delete from history

Technical Considerations

• Local storage (CoreData or JSON files)
• Thumbnail generation for previews
• Search/filter by title or date

Acceptance Criteria

• Auto-save comparisons
• History panel with thumbnails
• Load comparison from history
• Delete individual items

Story Points

5 points