fix(locations): size card to content instead of full viewport

The page forced the card to fill the viewport via h-[calc(100vh-...)],
leaving awkward empty space when few bins were present. Drop the fixed
height so the card sizes to its tallest column and let the page scroll
naturally if the bin grid overflows.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/web/src/pages/Locations.tsx

@@ -45,12 +45,12 @@ export default function Locations() {
   );
 
   return (
-    <div className="flex h-[calc(100vh-var(--spacing-topbar,3.25rem)-3rem)] flex-col gap-4">
+    <div className="flex flex-col gap-4">
       <PageHeader
         title="Locations"
         description="Sites → Rooms → Bins. Pick a room to see its bins."
       />
-      <div className="grid min-h-0 flex-1 grid-cols-[18rem_1fr] overflow-hidden rounded-lg border border-border bg-card">
+      <div className="grid grid-cols-[18rem_1fr] overflow-hidden rounded-lg border border-border bg-card">
         <div className="border-r border-border">
           <SiteRoomTree
             siteId={siteId}
@@ -60,9 +60,9 @@ export default function Locations() {
             canEdit={canEdit}
           />
         </div>
-        <div className="flex min-h-0 flex-col">
+        <div className="flex flex-col">
           <Breadcrumb siteName={siteName} roomName={roomName} />
-          <div className="min-h-0 flex-1 overflow-y-auto">
+          <div className="flex-1">
             {roomId ? (
               <BinGrid roomId={roomId} canEdit={canEdit} />
             ) : (