Fold review details

prompt.md

@@ -25,6 +25,13 @@ fixes exactly when it is not `Yes`, and Minor issues alone never block. For UI
 changes, check that the result is aligned, clean, and pixel-perfect, and that
 included screenshots prove the intended result was achieved.
 
+The review must read at a glance: everything outside `<details>` blocks totals
+under 512 bytes. Keep only the assessment line, the section headings, and a
+one-line `@bot` instruction visible. Put each strength, each issue, and each
+recommendation in its own top-level `<details>` block, never inside a list item,
+with a `<summary>` of the `file:line` and a few words and the what, why, and how
+inside. The template's `**Reasoning:**` goes in a `<details>` block too.
+
 For an `issue_comment` or `pull_request_review_comment` event, treat the `body`
 in the triggering comment payload below as the user's exact instruction.