0.11.6 — the proof is an action

Two versions ago we assumed that the end of the text in view meant the end of the reading. On a short entry and a tall screen the sentinel drifts into view immediately — the whole text fits on the screen before anyone has read the first sentence. That is exactly how the mark leapt out mid-reading.

**Visibility is no proof of attention.** You can see the end of a text and be at its beginning. You can scroll down to check how long an entry is and come back up. The viewport tells you where the page is, not where the eyes are.

**Certainty comes only from an action.** A click on a link, a poll button, a rating star — something a person does once they are done with the text. By then the attention has already left, and it can be caught without interrupting anything.

**If the click leads to another page, the animation has no time to play.** So a mark that was granted and not shown waits in browser storage and floats up right after the next page loads. The reward catches up with the reader wherever they went.

The listener sits on `pointerdown` in the capture phase — it has to run before navigation, and `click` can already be too late. This is one of those places where the order of browser events stops being trivia and becomes a condition of working at all.