Toolbar: no cap on pinned buttons (Fixes #323) (#326)

* Toolbar: no cap on pinned buttons (Fixes #323)

Every pinned command gets a toolbar button; `promoted()` is only the
default layout of a fresh or reset toolbar. A toolbar too narrow for every
button now collapses panels into their drop-down (one button that opens it,
listing every command, pinned ones included) from the right, then moves the
last panels into the » menu, instead of pushing a wide panel and everything
after it into ». Nothing is dropped.

Scenario s48 pins ten commands into SOLID > CREATE: all ten show at a wide
window, a narrow one collapses CREATE into its drop-down (all ten listed),
narrower still puts it in », and Reset Toolbar restores the defaults.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01RjGw4gA5ZvKrU8MQP6sBgT

* Narrow-toolbar test: panels collapse into their drop-down before »

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01RjGw4gA5ZvKrU8MQP6sBgT

* kernel: drop a needless borrow that fails clippy -D warnings on the current stable

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01RjGw4gA5ZvKrU8MQP6sBgT

---------

Co-authored-by: Claude Opus 5.5 <[email protected]>

crates/kernel/src/polyhedron.rs

@@ -532,7 +532,7 @@ fn shell_opened(b: &Body, healed: &Body, open: &[Vec3], opened: &[usize], thickn
     match r {
         Ok(Some(r)) => {
             // Over `[healed]`, the cavity's faces offsets of the faces they line; then over `[b]`.
-            Ok(record::after(hollowed(r, &healed, offsets(&cavity)), &healed, &record::counts(&[b])))
+            Ok(record::after(hollowed(r, healed, offsets(&cavity)), healed, &record::counts(&[b])))
         }
         Ok(None) => Err(KernelError::Failed("the shell removed everything".into())),
         // Healing can leave faces the boolean dislikes (revolved patches): the body as it was,