Keep a loop item's property from being read as a prop of the same name

A component that renders a list, such as FeatureGrid, passes each item
into a child: title={item.title || item.label || "Feature"}. The
compiler decided whether that attribute needed a client binding by
searching the expression for each prop name, so `item.label` matched the
grid's own `label` prop and a binding was emitted.

On hydration the binding is re-evaluated where the loop item is out of
scope, so the expression fell through to its default and replaced the
server's value: every card's title became "Feature". A name after a dot
belongs to whatever precedes it, so it no longer counts as a reference.

Timeline headings follow the same idea: its items were always h4, which
skipped a level and broke the heading order of a page that gives the
timeline no title of its own. They now take h3 in that case.

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

packages/ui/components/Timeline.wrn

@@ -58,7 +58,17 @@ component Timeline {
             >
               <div class="wrn-timeline__card-header">
                 <div>
-                  <h4 class="wrn-timeline__item-title">{item.title || item.label}</h4>
+                  <!--
+                    Items sit under this component's own title when it has one.
+                    Without that title they are the first heading here, so they
+                    take its level instead of skipping one and leaving a gap in
+                    the page's heading order.
+                  -->
+                  {#if title}
+                    <h4 class="wrn-timeline__item-title">{item.title || item.label}</h4>
+                  {:else}
+                    <h3 class="wrn-timeline__item-title">{item.title || item.label}</h3>
+                  {/if}
                   {#if item.subtitle}
                     <p class="wrn-timeline__subtitle">{item.subtitle}</p>
                   {/if}