The base small rule set --app-font-size: 0.875em but never consumed it,
so <small> elements fell back to the browser default ("smaller", roughly
0.83em of the parent). That made hints under fields visually drift
depending on the parent context — most noticeably on the telemetry page
where the muted hint, the per-field hint inside a label, and the caption
under a fieldset all rendered slightly different sizes.
The codebase already standardises on var(--text-xs) wherever a small was
explicitly styled (gridjs, footer, docs); this commit just makes the
default match that convention so every bare <small> is 12px regardless
of where it sits.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>