{# The shell diagram — one SVG, both languages. Same contract as `_diagram.html`: the geometry lives here once, and every word that is prose comes from `t.shell`, which `build.py` carries per language. Block names, tag names and file names stay literal — they are code, and code is not translated. Everything sits inside one `data-lit="true"` group, which is what lets `data-accent` reach `--primary` in brand.css. Accent marks the slots an app fills; the rest is what the shell owns. No classes anywhere in it. #}