Record the tenth sweep, over the deferred request system

docs/HANDOFF.md

@@ -4,10 +4,22 @@ Where the work in flight stands. The settled layout design, the vocabulary
 and the measurement method are in `docs/LAYOUT.md`; what the review of #19
 found is in `docs/LAYOUT_LOG.md`.
 
+## A quality sweep of the deferred system is submitted on PR #19
+
+`layout/one-ask` is at `4cb6f68` in `/home/bob/repos/iris-deferred`. The tenth
+sweep is the first review of `76aaf06` through `0e838e9` -- the bound rules,
+the deferred request path and the invalidation fix. Ten findings, the largest
+two being a bound's held length looked up a second time through a value that
+could not promise the end it named (`Bound::at` `expect`ed it), and a bound in
+pixels pinning the rel base it is not read against. `docs/LAYOUT_LOG.md` has
+them all, with the two rules it tripped and left and two corpus questions for
+Bryan. Verified: format, clippy both ways, 197 and 201 tests, all three seed
+scans (69.02s, 174.87s, 330.39s), and the cold dump byte-identical to
+`0e838e9` across all 34,986 boxes.
+
 ## Performance sweep is submitted on PR #19
 
-`layout/one-ask` is at `0e838e9` in `/home/bob/repos/iris-deferred`. The fix
-keeps dependencies only for size requests the allocator uses, and borrows
+The performance fix is `0e838e9`. It keeps dependencies only for size requests the allocator uses, and borrows
 `Widgets::size_rules` rather than cloning both axes at every lookup. Used
 hints retain their reader dependency; adding a cap after layout is checked for
 both hinted and measured shares. Ordinary text measurement still tracks its
@@ -95,6 +107,8 @@ comparison work above, its review rounds past `cadfba0` are described in
   overflow its pixels asked for, said as the place the parent gives and
   sharing one comparison with the span; and `Image` grown in the generated
   trees, which is the only widget here whose hint is a length in pixels.
+- **The deferred request system's own sweep**, `4cb6f68` -- described at the
+  top of this file and in full in `docs/LAYOUT_LOG.md`.
 - **One ask, the root's included**, `0d03267` -- the root had a layout path
   of its own, so a rule that reads the box it is offered reached every widget
   but that one. `Placing::WINDOW` is the box nobody drew and `Placing::ask`
@@ -155,12 +169,11 @@ the name it is reachable by.
 
 **Always**, because they cost nothing: format, workspace clippy under
 `-D warnings` with and without `layout-diagnostics`, the workspace tests, and
-the **cold dump**. `layout_dump` over 400 depth-5 trees is **34,571** boxes
-since `2dba90b` grew images in the trees, and `0d03267` left every one of them
-byte-identical. It was 34,488 before the images; the fourth through eighth
-sweeps all repeated 34,492, which is a `wc -l` of the whole run rather than of
-its box lines, so count the lines that are a box
-(`grep -cE '^[0-9]+ [0-9]+ '`). It is the only thing that catches two
+the **cold dump**. `layout_dump` over 400 depth-5 trees is **34,986** boxes
+since `76aaf06` grew bounds in the trees. It was 34,571 from `2dba90b`, which
+grew the images, and 34,488 before those; the fourth through eighth sweeps all
+repeated 34,492, which is a `wc -l` of the whole run rather than of its box
+lines, so count the lines that are a box (`grep -cE '^[0-9]+ [0-9]+ '`). It is the only thing that catches two
 same-typed values being swapped, which is the failure mode of a rename or a
 move. The repair moved 650 of those boxes, all from the collapsed-share
 correction; every commit since has been byte-identical to `84dad21`.