Record the fifth #11 review

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

docs/IRIS_EXTRACTION_HANDOFF.md

@@ -5,8 +5,8 @@ Not a decisions log; delete it when the extraction is done.
 
 ## Read this first
 
-**Pull request #11 has been reviewed four times; the fourth is answered in
+**Pull request #11 has been reviewed five times; the fifth is answered in
-`29d390d` and the fifth has not arrived.** Check for one before doing anything
+`01a9b86` and a sixth has not arrived.** Check for one before doing anything
 else:
 
 ```sh
@@ -39,7 +39,7 @@ packing images into arrays like atlas pages, and a bindless `binding_array`
 - Agent fork: `git@git.arirex.me:iris-ai/iris.git`. The bot cannot push
   canonical; work in the fork and open PRs into `iris/iris:main`.
 - **#11** `split/11-texture-bindings`, worktree `/home/bob/repos/iris-pr11`,
-  head `29d390d`, nine commits on top of `0f6a28b`. Reviewed four times, all
+  head `01a9b86`, ten commits on top of `0f6a28b`. Reviewed five times, all
   answered.
 - **#12** `split/12-pointer-routing`, worktree `/home/bob/repos/iris-pr12`,
   head `028521b`. A scroll falling through a hovered button. Not reviewed as
@@ -58,8 +58,8 @@ shape:
   `Textures` holds standalone images only.
 - **A primitive registers itself by being drawn.** The type carries its own
   WGSL and `PrimitiveRegistry` keys ids by `TypeId`, so the kind comes from the
-  type and there are no `RECT`/`GLYPH`/`TEXTURE` constants. Built-ins are
+  type and there are no `RECT`/`GLYPH`/`TEXTURE` constants. Nothing is seeded,
-  seeded up front only so first-draw order cannot shuffle them.
+  so an id depends on what a ui drew first and a ui pays only for what it uses.
 - **Nothing dispatches dynamically.** Push, free, renumber, upload and draw are
   identical for every primitive; only the entry size and the pipeline differ,
   and those are data. `InstanceList` carries a runtime stride and its data as
@@ -72,12 +72,13 @@ shape:
   recorded at write time; no other pipeline mentions textures at all.
 - **`shader.wgsl` became `shader/prelude.wgsl` plus one file per primitive**,
   because one module cannot declare two types at the same binding. The prelude
-  carries the window, masks, atlas, sampler, vertex shader and `masked()`, and
+  carries only what every primitive uses -- window, masks, vertex shader,
-  is the one place binding numbers are written down.
+  `masked()` -- and its header records the group 0 binding numbers; the atlas
-- **Order within a layer means nothing** and nothing claims otherwise -- but
+  and sampler are declared by the shaders that read them.
-  the widgets do rely on it today, since a `Text` over a `Rect` in one layer
+- **Order within a layer means nothing**, and the widgets do not rely on it:
-  only works because glyph registers after rect. Open question, raised on the
+  `Stack` gives each child its own layer and `TextEdit` draws its view in a
-  PR: text may need a layer of its own.
+  child layer above the selection rectangles. Verified with a ui that
+  registers glyph before rect.
 
 ## Standing instructions from the owner