- Update frontend tag filter to cycle through include/exclude/clear states
- Add backend support for tag_include and tag_exclude query parameters
- Maintain backward compatibility with legacy tag parameter
- Store tag states as dictionary with 'include'/'exclude' values
- Update test matrix documentation to reflect new tag behavior
The changes enable more granular tag filtering where users can now explicitly include or exclude specific tags, rather than just adding tags to a simple inclusion list. This provides better control over search results and improves the filtering user experience.
