Fix review system: display real names and check approval status

Changes:
- ProductReviews.tsx: Use LEFT JOIN and fetch reviewer_name field
- ReviewModal.tsx: Store reviewer_name at submission time
- ProductDetail.tsx: Check is_approved=true in checkUserReview()
- Add migration for reviewer_name column and approval index

This fixes two issues:
1. Reviews now show real account names instead of "Anonymous"
2. Members no longer see "menunggu moderasi" after approval

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/pages/ProductDetail.tsx

@@ -162,14 +162,15 @@ export default function ProductDetail() {
 
   const checkUserReview = async () => {
     if (!product || !user) return;
-    
+
     const { data } = await supabase
       .from('reviews')
       .select('id')
       .eq('user_id', user.id)
       .eq('product_id', product.id)
+      .eq('is_approved', true)
       .limit(1);
-    
+
     setHasReviewed(!!(data && data.length > 0));
   };