feat: add Priority 3 demos to components showcase page

Add live demos for:
- Product Gallery with image navigation and thumbnails
- Variant Selector with size buttons and color swatches
- Product Info with title, price, rating, stock status
- Product Tabs with description, specifications, reviews

Add demoProductDetail state with full product data including
images, sizes, colors, specifications, and sample reviews.

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

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

static/admin/js/components.js

@@ -149,6 +149,80 @@ function adminComponents() {
             this.demoCart.total = this.demoCart.subtotal;
         },
 
+        // Product Detail Demo (Priority 3)
+        demoProductDetail: {
+            id: 1,
+            name: 'Premium Wireless Headphones',
+            sku: 'WH-1000XM5',
+            price: 349.99,
+            sale_price: 279.99,
+            rating: 4.7,
+            review_count: 1247,
+            stock: 23,
+            is_new: true,
+            short_description: 'Industry-leading noise cancellation with exceptional sound quality. 30-hour battery life.',
+            description: '<p>Experience the next level of silence with our Premium Wireless Headphones. Industry-leading noise cancellation technology lets you focus on what matters most.</p><p>With up to 30 hours of battery life, you can enjoy your favorite music all day long. The soft, pressure-relieving ear pads provide all-day comfort.</p>',
+            features: [
+                'Industry-leading noise cancellation',
+                '30-hour battery life',
+                'Hi-Res Audio certified',
+                'Multipoint connection',
+                'Speak-to-chat technology'
+            ],
+            specifications: [
+                { name: 'Driver Size', value: '40mm' },
+                { name: 'Frequency Response', value: '4Hz - 40,000Hz' },
+                { name: 'Battery Life', value: '30 hours' },
+                { name: 'Charging Time', value: '3 hours' },
+                { name: 'Weight', value: '250g' },
+                { name: 'Connectivity', value: 'Bluetooth 5.2, 3.5mm' }
+            ],
+            images: [
+                { id: 1, url: 'https://images.unsplash.com/photo-1505740420928-5e560c06d30e?w=800&h=800&fit=crop', alt: 'Headphones front view' },
+                { id: 2, url: 'https://images.unsplash.com/photo-1484704849700-f032a568e944?w=800&h=800&fit=crop', alt: 'Headphones side view' },
+                { id: 3, url: 'https://images.unsplash.com/photo-1583394838336-acd977736f90?w=800&h=800&fit=crop', alt: 'Headphones with case' },
+                { id: 4, url: 'https://images.unsplash.com/photo-1546435770-a3e426bf472b?w=800&h=800&fit=crop', alt: 'Person wearing headphones' }
+            ],
+            sizes: [
+                { id: 1, name: 'Standard', value: 'standard', stock: 23 },
+                { id: 2, name: 'Compact', value: 'compact', stock: 8 }
+            ],
+            colors: [
+                { id: 1, name: 'Black', value: 'black', color_hex: '#1a1a1a', stock: 15 },
+                { id: 2, name: 'Silver', value: 'silver', color_hex: '#C0C0C0', stock: 8 },
+                { id: 3, name: 'Midnight Blue', value: 'blue', color_hex: '#191970', stock: 0 }
+            ],
+            reviews: [
+                {
+                    id: 1,
+                    author_name: 'John D.',
+                    rating: 5,
+                    title: 'Best headphones I\'ve ever owned',
+                    content: 'The noise cancellation is incredible. I use these for work calls and they block out everything. Battery life is amazing too.',
+                    verified: true,
+                    created_at: '2025-01-15',
+                    helpful_count: 42
+                },
+                {
+                    id: 2,
+                    author_name: 'Sarah M.',
+                    rating: 4,
+                    title: 'Great sound, slightly tight fit',
+                    content: 'Sound quality is phenomenal. My only complaint is they feel a bit tight after a few hours. Otherwise perfect.',
+                    verified: true,
+                    created_at: '2025-01-10',
+                    helpful_count: 18
+                }
+            ],
+            rating_distribution: { 5: 68, 4: 22, 3: 6, 2: 3, 1: 1 },
+            category: { name: 'Headphones', slug: 'headphones', url: '/category/headphones' },
+            vendor: { name: 'AudioTech', slug: 'audiotech', url: '/vendor/audiotech' }
+        },
+        selectedImage: 0,
+        selectedSize: null,
+        selectedColor: null,
+        activeProductTab: 'description',
+
         // Sample form data for examples
         exampleForm: {
             textInput: 'Sample text',