feat: types ImageItem + dépendances heic2any jszip

- Install heic2any and jszip dependencies
- Create src/types/images.ts with ImageItem, ImageStatus, ImageProgress, and ZipEntry types
- heic2any includes bundled TypeScript types (no declaration file needed)
- ImageItem is the central data model for the image processing module with support for:
  - HEIC to JPEG conversion
  - AI-powered background removal
  - Shopify product lookup and upload
  - Progress tracking and error handling
  - Rotation and feather adjustments (cached PNG blob for fast re-processing)

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

package.json

@@ -17,6 +17,8 @@
     "@prisma/client": "^7.8.0",
     "bcryptjs": "^3.0.3",
     "better-sqlite3": "^12.10.0",
+    "heic2any": "^0.0.4",
+    "jszip": "^3.10.1",
     "next": "14.2.35",
     "next-auth": "^4.24.14",
     "react": "^18",