feat(images): Add local image storage with on-demand resizing

- Store product images locally with hierarchy: /images/products/<state>/<store>/<brand>/<product>/
- Add /img/* proxy endpoint for on-demand resizing via Sharp
- Implement per-product image checking to skip existing downloads
- Fix pathToUrl() to correctly generate /images/... URLs
- Add frontend getImageUrl() helper with preset sizes (thumb, medium, large)
- Update all product pages to use optimized image URLs
- Add stealth session support for Dutchie GraphQL crawls
- Include test scripts for crawl and image verification

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

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

backend/src/index.ts

@@ -7,6 +7,7 @@ import { initializeImageStorage } from './utils/image-storage';
 import { logger } from './services/logger';
 import { cleanupOrphanedJobs } from './services/proxyTestQueue';
 import healthRoutes from './routes/health';
+import imageProxyRoutes from './routes/image-proxy';
 
 dotenv.config();
 
@@ -29,6 +30,10 @@ app.use(express.json());
 const LOCAL_IMAGES_PATH = process.env.LOCAL_IMAGES_PATH || './public/images';
 app.use('/images', express.static(LOCAL_IMAGES_PATH));
 
+// Image proxy with on-demand resizing
+// Usage: /img/products/az/store/brand/product/image.webp?w=200&h=200
+app.use('/img', imageProxyRoutes);
+
 // Serve static downloads (plugin files, etc.)
 // Uses ./public/downloads relative to working directory (works for both Docker and local dev)
 const LOCAL_DOWNLOADS_PATH = process.env.LOCAL_DOWNLOADS_PATH || './public/downloads';