fix: prevent documents row from causing horizontal scroll on mobile

- Shorten button labels ("New document" → "New", "Upload attachment" → "Upload") on small screens
- Add min-w-0 and shrink-0 to flex containers and items to prevent overflow
- Truncate document revision text on narrow viewports
- Mark chevron, key badge, and action buttons as shrink-0

Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/pages/IssueDetail.tsx

@@ -672,7 +672,12 @@ export function IssueDetail() {
         )}
       >
         <Paperclip className="h-3.5 w-3.5 mr-1.5" />
-        {uploadAttachment.isPending || importMarkdownDocument.isPending ? "Uploading..." : "Upload attachment"}
+        {uploadAttachment.isPending || importMarkdownDocument.isPending ? "Uploading..." : (
+          <>
+            <span className="hidden sm:inline">Upload attachment</span>
+            <span className="sm:hidden">Upload</span>
+          </>
+        )}
       </Button>
     </>
   );