apps/web/public/images was shipping ~90 MB of source art (enemies, npc,
combat status icons, HUD icon originals/difficulty badges, unused
background paintings) that no component, template, or stylesheet
actually references, since Angular copies public/ verbatim into every
browser build. Moved everything not referenced under apps/web/src to a
new art/ directory at the repo root, preserving the original subfolder
layout; only the 11 files actually loaded by the app (runtime HUD/
background derivatives and their PNG fallbacks) remain under
apps/web/public/images. Documented the split in README.md.
