Add blog thumbnail and banner upload endpoints with storage keys.

Store image filenames in DB, resolve paths for cleanup on replace/delete, and reuse product-thumb multer limits.

backend/src/config/uploadPaths.ts

@@ -31,6 +31,20 @@ export const variantImagesUrlPrefix = '/uploads/public/variants/images/';
 
 export const getVariantImagePublicUrl = (filename: string): string => `${variantImagesUrlPrefix}${filename}`;
 
+export const getBlogImagesDir = (): string => join(getPublicUploadsDir(), 'blog', 'images');
+
+export const blogImagesUrlPrefix = '/uploads/public/blog/images/';
+
+export const getBlogImagePublicUrl = (filename: string): string => `${blogImagesUrlPrefix}${filename}`;
+
+export const resolveBlogImagePath = (storageKey: string): string => {
+    const baseDir = getBlogImagesDir();
+
+    const absolutePath = resolvePathWithinDir(baseDir, storageKey);
+
+    return absolutePath;
+};
+
 export const getShopBrandingDir = (): string => join(getPublicUploadsDir(), 'shop');
 
 export const shopBrandingUrlPrefix = '/uploads/public/shop/';