- Replace content-aware extractCleanTemplate with structure-only extractStructureSignature for template comparison
- Add extractTemplateForStorage to preserve actual content for meaningful template display
- Update generateTemplateSignature to use purely structural comparison ignoring text content
- Remove redundant extractClassSignature function (functionality moved to extractStructureSignature)
- Resolves issue where identical DOM structures created multiple templates due to content differences
- Knowledge cards and other collections now correctly deduplicate to single templates while preserving content for previews