0.31.0: a section that needs a long page

`PinnedPoints` is a stack of frames on the left and three points pinned on the right. The frames scroll, the points hold: a reader three screens into the evidence still has the claim they are looking at it for.

The section came out of a specific problem. A long stretch of proof loses its own thesis by the third picture — the reader remembers being shown something and no longer remembers why.

The warning in the catalogue

This section carries a caveat the others do not: **it needs the page to be long.** With two frames the right column never unsticks and the pinning reads as an accident. Four or five is where it earns itself; below that, a simpler spread says the same thing.

That is part of the general rule: a section is chosen by the shape of the content, not by how it looks. A section short of material does not read as restrained, it reads as broken.

What it reminded us of on the way

It is the only section that renders its own `<section>`, and that walked straight into a known trap: the section wrapper clips overflow, and clipping kills sticky outright. The trap was written down. It was read, argued away, and then measured: the column moved a thousand pixels for every thousand pixels of scroll, with the markup still saying sticky.

The second reminder: the inward padding is for words. Put it on a whole column and every frame in it stops short of the guide it should sit on, and the grid drifts.