Fabric.js design canvas implementation and supporting infrastructure

Design Canvas (Primary)
- FabricDesignCanvasV2: Fabric.js-based product customization canvas
  - Lazy-loads Fabric.js to minimize bundle impact
  - Renders product mockup with print area guide (magenta dashed box)
  - Supports front/back view switching with correct product images
  - Color swatch selection for garment customization
  - Text element creation with selection handles and transform controls
  - Fixed React dependency array to prevent infinite renders

Support Components
- DesignCanvasWrapper: Client-side wrapper for SSR compatibility
- DesignCanvasErrorBoundary: Error boundary for canvas failures
- ThemeInitializer: Theme detection and application

Configuration
- Updated .claude/launch.json with dev server settings
- Updated .claude/settings.local.json with local preferences
- Updated next.config.mjs for production build optimization
- Dependency updates in package.json and package-lock.json

Known Issues & TODO
- Image element rendering disabled (Fabric.js compatibility investigation)
- Text editing UI controls needed (font, size, color pickers)
- Delete/undo functionality pending
- Print area alignment needs visual verification
- "Add to Cart" integration with design serialization pending

Testing Artifacts
- check_*.js: Product verification scripts for debugging

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

src/app/admin/designs/[id]/edit/page.tsx

@@ -4,33 +4,14 @@ import { useState, useEffect } from 'react';
 import { useRouter } from 'next/navigation';
 import Link from 'next/link';
 import dynamic from 'next/dynamic';
+import type { ProductDTO } from '@/lib/types';
 
 interface DesignApproval {
   id: string;
   customerEmail: string;
   customerName: string | null;
   productId: string;
-  product: {
-    id: string;
-    name: string;
-    basePrice: number;
-    personalisedPrice: number;
-    onSale: boolean;
-    effectivePrice: number;
-    colors: string[];
-    sizes: string[];
-    showOnPersonalised: boolean;
-    imageUrl: string | null;
-    imageUrlBack: string | null;
-    photoRecolorable: boolean;
-    colorPhotos: Record<string, string>;
-    colorPhotosBack: Record<string, string>;
-    printArea: string;
-    printAreaBack: string | null;
-    mockup: string;
-    referenceWidthCm: number | null;
-    referenceHeightCm: number | null;
-  };
+  product: ProductDTO;
   designJson: string;
   color: string;
   size: string | null;