Extend Recently Reviewed card to match sibling heights

Use flex-1 on the Recently Reviewed card so it stretches to fill the
remaining vertical space in the left column, aligning its bottom with
Juror Workload and Activity Feed. Add className prop to AnimatedCard.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/observer/observer-dashboard-content.tsx

@@ -350,7 +350,7 @@ export function ObserverDashboardContent({ userName }: { userName?: string }) {
       {/* Middle Row */}
       <div className="grid grid-cols-1 gap-6 lg:grid-cols-3">
         {/* Left column: Score Distribution + Recently Reviewed stacked */}
-        <div className="space-y-6">
+        <div className="flex flex-col gap-6">
           {/* Score Distribution */}
           <AnimatedCard index={7}>
             <Card>
@@ -397,8 +397,8 @@ export function ObserverDashboardContent({ userName }: { userName?: string }) {
           </AnimatedCard>
 
           {/* Recently Reviewed */}
-          <AnimatedCard index={10}>
-            <Card>
+          <AnimatedCard index={10} className="flex-1 flex flex-col">
+            <Card className="flex-1 flex flex-col">
               <CardHeader className="pb-3">
                 <CardTitle className="flex items-center gap-2.5 text-base">
                   <div className="rounded-lg bg-emerald-500/10 p-1.5">