Merge pull request #613 from codeslash-dev/claude/test-coverage-layout-fix-fz7p45

docs: add container-type to grid demo section

Author: jackgranatowski

docs/test-coverage-3-layout.html

@@ -141,7 +141,7 @@ <h2>Switcher</h2>
     </section>
 
     <!-- GRID -->
-    <section class="demo-section">
+    <section class="demo-section" style="container-type: inline-size">
       <h2>Grid — auto-fill min-width tiers</h2>
       <div class="sf-stack sf-stack--m">
         <div><span class="demo-note">.sf-grid--xs</span><div class="sf-grid sf-grid--xs demo-wrap"><div class="demo-box">1</div><div class="demo-box">2</div><div class="demo-box">3</div><div class="demo-box">4</div><div class="demo-box">5</div></div></div>