refactor(css): consolidate .expand-commit into shared mobile media query

Was in a standalone @media (max-width: 960px) block; now lives inside
the existing mobile breakpoint block alongside sibling expand-row rules.
No visual change.

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

website/static/style.css

@@ -793,12 +793,6 @@ th[data-sort].sort-asc::after {
   display: none;
 }
 
-@media (max-width: 960px) {
-  .expand-commit {
-    display: inline;
-  }
-}
-
 .tag {
   position: relative;
   border: 1px solid transparent;
@@ -1047,6 +1041,10 @@ th[data-sort].sort-asc::after {
     display: none;
   }
 
+  .expand-commit {
+    display: inline;
+  }
+
   .tag-group {
     display: none;
   }