Point the handoff at b7b8d09

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/HANDOFF.md

@@ -6,8 +6,8 @@ found is in `docs/LAYOUT_LOG.md`.
 
 ## The Iris layout repair is submitted
 
-**Iris PR #19** (`layout/one-ask`) replaces closed #18. The tip is `1096c31`,
+**Iris PR #19** (`layout/one-ask`) replaces closed #18. The tip is `b7b8d09`,
-and past the reviewed `cadfba0` it is seven rounds, each described in
+and past the reviewed `cadfba0` it is eight rounds, each described in
 `docs/LAYOUT_LOG.md`:
 
 - **The repair**, `add6774` and `84dad21` -- collapsed-share placement,
@@ -28,6 +28,10 @@ and past the reviewed `cadfba0` it is seven rounds, each described in
   it out, a surface configured under its own texture, a counter naming the
   wrong contract, things nothing reads, and a question asked through a value
   rather than a reference.
+- **A sweep over the shader boundary and the position widgets**, `b7b8d09` --
+  two constants the shader and the CPU both count in written twice, and a
+  `Scroll` positioning content the framework positions, which cost a redraw
+  at the default alignment.
 
 The settled design of the last three is in `docs/LAYOUT.md` under "Three
 names, and the one argument that says them". Bryan settled the API over