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>

check_color_mismatch.js

@@ -0,0 +1,41 @@
+const { PrismaClient } = require('@prisma/client');
+const prisma = new PrismaClient();
+
+async function main() {
+  const product = await prisma.product.findUnique({
+    where: { slug: 'awd-t-shirt-at001' },
+    select: {
+      colorPhotos: true,
+      colorPhotosBack: true
+    }
+  });
+
+  const front = JSON.parse(product.colorPhotos);
+  const back = JSON.parse(product.colorPhotosBack || '{}');
+  
+  console.log('Front colors:', Object.keys(front).sort());
+  console.log('Back colors:', Object.keys(back).sort());
+  
+  const allColors = new Set([...Object.keys(front), ...Object.keys(back)]);
+  
+  console.log('\nMissing in back:');
+  Object.keys(front).forEach(color => {
+    if (!back[color]) {
+      console.log(`  ${color} (front has it, back is MISSING)`);
+    }
+  });
+  
+  console.log('\nExtra in back (no front):');
+  Object.keys(back).forEach(color => {
+    if (!front[color]) {
+      console.log(`  ${color} (back has it, front is missing)`);
+    }
+  });
+}
+
+main()
+  .then(() => process.exit(0))
+  .catch(err => {
+    console.error(err);
+    process.exit(1);
+  });