/atlas — add filter chips by type + author + model

[caiovicentino]

Currently /atlas groups by type but doesn't filter. As entries grow past ~30 this will be unusable.

v1: client-side filter chips for type (5 enum), model_id (free-text), author (free-text from entries).
v2: full-text search over title + claim via Fuse.js (already a dep).