Lay out a scroll container's content when the content changes

A short list opened after a long one drew all its rows stacked on one
point. The fault was not in the list tab: rebuild() handed the row stack
to setContent() while it was still empty, so the content was sized to
max(rows, viewport) = the viewport. The rows arrived after that, and for
a short list the same formula yields the same height, so resize() saw no
change and skipped layout(). A long list changes the height and never
showed it.

relayoutContent() now runs whenever the content changed, rather than
leaning on resize()'s change detection - that detection is the wrong
instrument for "the children moved".

The list tab was the only affected caller: the panels use ListView,
which positions its rows itself, and the inspector fills its body
before setContent.

Also drops the comma line under the list. Every section that can carry a
list supplies openList, so the comma fallback in fieldFactory was
unreachable; listToText/listFromText go with it. The list-value test now
covers coerceListItem through coerceValue instead, so the boolean
spelling stays guarded.

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

src/core/graph/nodes/data/ListLiteral.ts

@@ -6,7 +6,7 @@ export const ListLiteral: NodeDef = {
   type: 'List',
   label: 'List',
   category: 'data',
-  description: 'A constant list, typed as one comma-separated line.',
+  description: 'A constant list, edited item by item in the List tab.',
   inputs: [],
   outputs: [list('value')],
   params: [{ key: 'value', label: 'Value', kind: 'list', default: [], items: 'number' }],