Record the refcount removal beside the sweep that raised it

docs/HANDOFF.md

@@ -6,10 +6,10 @@ found is in `docs/LAYOUT_LOG.md`.
 
 ## A sweep for allocation, and the cost per child, is on #19
 
-The fourteenth sweep landed at `97fca76`. It read the whole branch again,
-aimed first at what allocates and then at whatever the reading turned up.
-Eight findings, the largest two both about cost per thing rather than per
-frame:
+The fourteenth sweep landed at `97fca76`, with the refcount removal below at
+`429a4f1`. It read the whole branch again, aimed first at what allocates and
+then at whatever the reading turned up. Nine findings, the largest two both
+about cost per thing rather than per frame:
 
 - **A container's draw was quadratic in its children.** Five per-child steps
   each asked "have I done this one already?" by searching a list; at 1,600
@@ -38,14 +38,21 @@ changed; and two comments this branch's own commits falsified -- one saying
 `widget_trait!` takes no attributes after `76aaf06` taught it to, one saying
 `Scroll` clips when masking is a capability a caller opts into with `Masked`.
 
+The ninth is the one Bryan asked for on 2026-09-21, having first been left for
+the pre-gate pass: `StrongWidget` allocated a `RefCounter(Arc<AtomicU32>)` it
+could never use, since it deliberately has no `Clone`, so every widget paid a
+heap allocation and two atomic read-modify-writes for a count that stayed at
+zero. It is the id, the sender and the type now, and `Drop` sends;
+`size_of::<StrongWidget>()` is 32 rather than 40. `RefCounter` stays for
+`TextureHandle`, which does clone, trimmed to what that needs.
+
 It also left five things, with the numbers. Text allocates about six times per
 re-broken paragraph per frame, and removing all of them is **0.07%** of
 instructions (3.7107B to 3.7081B over 500 sweeping resize frames of 40
 paragraphs), so the count is recorded rather than the machinery built --
 allocation count and cost are not the same quantity, and this is where they
-part. `StrongWidget` carries an `Arc<AtomicU32>` it can never use, since it has
-no `Clone`; that and seven dead items older than #19 are listed under the
-pre-gate review below rather than fixed here.
+part. Seven dead items older than #19 are listed under the pre-gate review
+below rather than fixed here.
 
 `docs/LAYOUT_LOG.md` has all of it. Verified: format, clippy both ways, 190
 ordinary, 193 diagnostic and 189 release tests, the cold dump byte-identical to
@@ -287,9 +294,10 @@ comparison work above, its review rounds past `cadfba0` are described in
 - **A full sweep of the branch**, `cbccfb6` -- a length of zero that printed
   as nothing, a ceiling that stepped off the top of the grid, and a harness
   setter that dropped the bound beside the length it set.
-- **A sweep for allocation and the cost per child**, `97fca76` -- a
-  container's draw quadratic in its children, and a mask's rectangle resolved
-  once per fragment. Described at the top of this file.
+- **A sweep for allocation and the cost per child**, `97fca76` and `429a4f1`
+  -- a container's draw quadratic in its children, a mask's rectangle resolved
+  once per fragment, and the refcount a widget handle can never raise.
+  Described at the top of this file.
 
 The settled design of the vocabulary rounds is in `docs/LAYOUT.md` under
 "Three names, and the one argument that says them". Bryan settled the API
@@ -401,13 +409,9 @@ a compile error, which reads exactly like a fuzzer failure.
    grammars of which `core/src/util/vec2.rs` uses two, one line apart.
    `Align` now has `Index<Axis>`, so the `if let Some` each
    `partial_align` writes twice collapses when that sweep reaches them.
-   The fourteenth sweep adds more: `StrongWidget` allocates an
-   `Arc<AtomicU32>` refcount it can never use, because it deliberately has no
-   `Clone`, so every widget pays a heap allocation and two atomic
-   read-modify-writes for a count that stays at zero, and `StrongWidget::refs`
-   has no caller; and `Size::to_uivec2`, `Size::rel`, `Size::leftover`,
-   `Len::to_uivec2`, `Vec2::with_x`, `Vec2::with_y`, `Vec2::ceil` and
-   `Layers::iter_orderless_mut` are all dead.
+   The fourteenth sweep adds more, all dead: `Size::to_uivec2`, `Size::rel`,
+   `Size::leftover`, `Len::to_uivec2`, `Vec2::with_x`, `Vec2::with_y`,
+   `Vec2::ceil` and `Layers::iter_orderless_mut`.
 3. **Integrate the app's Iris capabilities before changing its pin.**
    `32f6ad8` has 45 commits not reachable from the review branch; shared UI
    ownership, richer masks, Android support, and app-side performance work