feat(ui): min(), max() and clamp(); insets as percentages of the containing block

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

changes/defaults-views-templates.md

@@ -92,6 +92,8 @@ What a game's screens found missing, now in `ludic.ui`:
 - `text-fit: shrink MIN` shrinks a line to its box, then cuts it with an ellipsis; `line-height`;
   an `em` reads the font size the element ends with (a `font-size` later in the rule, or in a later
   rule), not the one it had so far;
+- `min()`, `max()` and `clamp()`, in `calc()` or on their own; `top` / `right` / `bottom` / `left`
+  as a percentage or a `calc()` of one, of the containing block;
 - a transition lands exactly on its end value (it had stopped a rounding error short of it, at every
   frame rate).