feat: add image upload functionality for articles

- Implemented image upload API in the article service, allowing users to upload images associated with articles.
- Added validation for image size and type, ensuring only supported formats (PNG, JPG, GIF, WebP) are accepted.
- Created a new Aliyun object storage client to handle image storage and retrieval.
- Updated the article handler to include an endpoint for image uploads.
- Enhanced error handling for image upload failures and added relevant error messages.
- Introduced public URL generation for stored images, allowing access via signed tokens.
- Updated localization files to include new messages related to image upload functionality.
- Added tests for image upload and retrieval processes.

apps/admin-web/src/i18n/messages/en-US.ts

@@ -406,6 +406,10 @@ const enUS = {
       coverHint: "Upload a cover asset before publishing. This is local preview only for now.",
       coverUpload: "Upload cover image",
       imagePrompt: "Enter image URL",
+      tablePicker: {
+        empty: "Drag to choose a table size",
+        hint: "Keep dragging near the edge to expand the grid",
+      },
       messages: {
         saved: "Article saved.",
         generating: "This article is still generating. Try editing it later.",