fix: Bug - Attachments gets syncronized corrupt

e2e/pages/chat-messages.page.ts

@@ -132,6 +132,31 @@ export class ChatMessagesPage {
     }).toBe(true);
   }
 
+  /** SHA-256 of the bytes currently served by the rendered chat image. */
+  async getMessageImageSha256(altText: string): Promise<string> {
+    const image = this.getMessageImageByAlt(altText);
+
+    return image.evaluate(async (element) => {
+      const img = element as HTMLImageElement;
+      const response = await fetch(img.src);
+      const buffer = await response.arrayBuffer();
+      const digest = await crypto.subtle.digest('SHA-256', buffer);
+
+      return [...new Uint8Array(digest)]
+        .map((byte) => byte.toString(16).padStart(2, '0'))
+        .join('');
+    });
+  }
+
+  /** Asserts the rendered chat image is byte-identical to the sent file. */
+  async expectMessageImageContentSha256(altText: string, expectedSha256: string): Promise<void> {
+    await this.expectMessageImageLoaded(altText);
+    await expect.poll(() => this.getMessageImageSha256(altText), {
+      timeout: 30_000,
+      message: `Image ${altText} should be received byte-identical (no truncated/corrupt transfer)`
+    }).toBe(expectedSha256);
+  }
+
   getEmbedCardByTitle(title: string): Locator {
     return this.page.locator('app-chat-link-embed').filter({
       has: this.page.getByText(title, { exact: true })