fix(dashboard): Limit file uploads to 1MB (#13981)

## Summary

**What** — What changes are introduced in this PR?

Limit file uploads to 1MB

**Why** — Why are these changes relevant or necessary?  

Prevent large file uploads in the Admin 

**How** — How have these changes been implemented?

Set size limits on the file uploads

**Testing** — How have these changes been tested, or how can the reviewer test the feature?

---

## Checklist

Please ensure the following before requesting a review:

- [ ] I have added a **changeset** for this PR
    - Every non-breaking change should be marked as a **patch**
    - To add a changeset, run `yarn changeset` and follow the prompts
- [ ] The changes are covered by relevant **tests**
- [ ] I have verified the code works as intended locally
- [ ] I have linked the related issue(s) if applicable

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## Additional Context

CLOSES CORE-1270


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> [!NOTE]
> Adds a 1MB default file size limit to `FileUpload`, surfaces size/type rejections in media forms via new i18n, and allows unlimited size for product import.
> 
> - **Components**:
>   - `components/common/file-upload/file-upload.tsx`:
>     - Add `maxFileSize` (default 1MB) and size validation; return `rejectedFiles` alongside valid files.
> - **Products › Media Upload**:
>   - `upload-media-form-item.tsx`:
>     - Handle `rejectedFiles` and set form errors for invalid type and oversized files.
> - **Products › Import**:
>   - `upload-import.tsx`: Use `maxFileSize={Infinity}` to disable size limit for CSV import.
> - **i18n**:
>   - Schema and EN translations: add `products.media.fileTooLarge` message.
> 
> <sup>Written by [Cursor Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit c8c67f4d329f8767e99694649bf0b3fe4cf400e9. This will update automatically on new commits. Configure [here](https://cursor.com/dashboard?tab=bugbot).</sup>

packages/admin/dashboard/src/components/common/file-upload/file-upload.tsx

@@ -8,21 +8,30 @@ export interface FileType {
   file: File
 }
 
+export interface RejectedFile {
+  file: File
+  reason: "size" | "format"
+}
+
 export interface FileUploadProps {
   label: string
   multiple?: boolean
   hint?: string
   hasError?: boolean
   formats: string[]
-  onUploaded: (files: FileType[]) => void
+  maxFileSize?: number // in bytes, defaults to 1MB. Set to Infinity to disable.
+  onUploaded: (files: FileType[], rejectedFiles?: RejectedFile[]) => void
 }
 
+const DEFAULT_MAX_FILE_SIZE = 1024 * 1024 // 1MB
+
 export const FileUpload = ({
   label,
   hint,
   multiple = true,
   hasError,
   formats,
+  maxFileSize = DEFAULT_MAX_FILE_SIZE,
   onUploaded,
 }: FileUploadProps) => {
   const [isDragOver, setIsDragOver] = useState<boolean>(false)
@@ -65,18 +74,26 @@ export const FileUpload = ({
     }
 
     const fileList = Array.from(files)
-    const fileObj = fileList.map((file) => {
-      const id = Math.random().toString(36).substring(7)
+    const validFiles: FileType[] = []
+    const rejectedFiles: RejectedFile[] = []
+    const normalizedMaxFileSize = Math.min(maxFileSize, Infinity)
 
+    fileList.forEach((file) => {
+      if (file.size > normalizedMaxFileSize) {
+        rejectedFiles.push({ file, reason: "size" })
+        return
+      }
+
+      const id = Math.random().toString(36).substring(7)
       const previewUrl = URL.createObjectURL(file)
-      return {
+      validFiles.push({
         id: id,
         url: previewUrl,
         file,
-      }
+      })
     })
 
-    onUploaded(fileObj)
+    onUploaded(validFiles, rejectedFiles)
   }
 
   const handleDrop = (event: DragEvent) => {