Better filtering UI

Not super clear what's being filtered, how to remove. Eg you can click 'python' in the listing and it filters to python but the UI doesn't do much of a job communicating that

Could implement similar to advisories eg https://advisories.ecosyste.ms/ecosystems/packagist?severity=CRITICAL

Start by reviewing the existing filtering UI, especially the interaction where clicking “python” applies a filter, and compare it with the linked advisories example. Done means users can clearly see which filters are active and understand how to remove them.

Written by the indexing model from the issue text.