feat: add image paste functionality to DescriptionImageDropZone component

- Implemented handlePaste function to process images from clipboard across all OS.
- Updated the component to handle pasted images and prevent default paste behavior.
- Enhanced user instructions to include pasting images in the UI.

Added a utility function to simulate pasting images in tests, ensuring cross-platform compatibility.

apps/app/tests/utils/files/drag-drop.ts

@@ -36,3 +36,47 @@ export async function simulateFileDrop(
     { selector: targetSelector, content: fileContent, name: fileName, mime: mimeType }
   );
 }
+
+/**
+ * Simulate pasting an image from clipboard onto an element
+ * Works across all OS (Windows, Linux, macOS)
+ */
+export async function simulateImagePaste(
+  page: Page,
+  targetSelector: string,
+  imageBase64: string,
+  mimeType: string = "image/png"
+): Promise<void> {
+  await page.evaluate(
+    ({ selector, base64, mime }) => {
+      const target = document.querySelector(selector);
+      if (!target) throw new Error(`Element not found: ${selector}`);
+
+      // Convert base64 to Blob
+      const byteCharacters = atob(base64);
+      const byteNumbers = new Array(byteCharacters.length);
+      for (let i = 0; i < byteCharacters.length; i++) {
+        byteNumbers[i] = byteCharacters.charCodeAt(i);
+      }
+      const byteArray = new Uint8Array(byteNumbers);
+      const blob = new Blob([byteArray], { type: mime });
+
+      // Create a File from Blob
+      const file = new File([blob], "pasted-image.png", { type: mime });
+
+      // Create a DataTransfer with clipboard items
+      const dataTransfer = new DataTransfer();
+      dataTransfer.items.add(file);
+
+      // Create ClipboardEvent with the image data
+      const clipboardEvent = new ClipboardEvent("paste", {
+        bubbles: true,
+        cancelable: true,
+        clipboardData: dataTransfer,
+      });
+
+      target.dispatchEvent(clipboardEvent);
+    },
+    { selector: targetSelector, base64: imageBase64, mime: mimeType }
+  );
+}