fix: resolve image upload ERR_ACCESS_DENIED and dialog a11y warning

Eagerly read file data into memory via arrayBuffer() before constructing
FormData for the upload fetch. Clipboard-paste File objects from the MDX
editor reference transient browser data that may be discarded after the
paste event handler returns; streaming that stale reference in the fetch
body causes net::ERR_ACCESS_DENIED. Reading into an ArrayBuffer first
makes the FormData self-contained.

Also suppress the Radix UI "Missing Description" console warning on the
NewIssueDialog by setting aria-describedby={undefined}.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui/src/api/assets.ts

@@ -2,9 +2,16 @@ import type { AssetImage } from "@paperclip/shared";
 import { api } from "./client";
 
 export const assetsApi = {
-  uploadImage: (companyId: string, file: File, namespace?: string) => {
+  uploadImage: async (companyId: string, file: File, namespace?: string) => {
+    // Read file data into memory eagerly so the fetch body is self-contained.
+    // Clipboard-paste File objects reference transient data that the browser may
+    // discard after the paste-event handler returns, causing ERR_ACCESS_DENIED
+    // when fetch() later tries to stream the FormData body.
+    const buffer = await file.arrayBuffer();
+    const safeFile = new File([buffer], file.name, { type: file.type });
+
     const form = new FormData();
-    form.append("file", file);
+    form.append("file", safeFile);
     if (namespace && namespace.trim().length > 0) {
       form.append("namespace", namespace.trim());
     }

ui/src/components/NewIssueDialog.tsx

@@ -237,6 +237,7 @@ export function NewIssueDialog() {
     >
       <DialogContent
         showCloseButton={false}
+        aria-describedby={undefined}
         className={cn(
           "p-0 gap-0 flex flex-col max-h-[calc(100vh-6rem)]",
           expanded