fix(comments): attach code comments on Enter

Code comments required Cmd/Ctrl+Enter while quotes and browser annotations used Enter. Align desktop submission and its placeholder, preserve Shift+Enter line breaks and mobile keyboard behavior.

Validated UI type-check, UI lint, and six existing IME checks. Lint reports one existing warning in MobileChangesSurface. In-app browser validation was unavailable.

packages/ui/src/components/comments/InlineCommentInput.tsx

@@ -39,7 +39,7 @@ export function InlineCommentInput({
   const { isMobile } = useDeviceInfo();
   const [text, setText] = React.useState(initialText);
   const textareaRef = useRef<HTMLTextAreaElement>(null);
-  const saveShortcut = formatShortcutForDisplay('mod+enter');
+  const saveShortcut = formatShortcutForDisplay('enter');
   void isEditing;
 
   const handleTextChange = (value: string) => {
@@ -124,9 +124,9 @@ export function InlineCommentInput({
   const handleKeyDown = (e: React.KeyboardEvent) => {
     if (isIMECompositionEvent(e)) return;
 
-    // As the placeholder promises: Cmd/Ctrl+Enter attaches, plain Enter
-    // breaks the line, Escape cancels.
-    if ((e.metaKey || e.ctrlKey) && e.key === 'Enter') {
+    // Desktop Enter attaches; Shift+Enter and mobile Enter break the line.
+    // Keep Cmd/Ctrl+Enter available for hardware keyboards on mobile.
+    if (e.key === 'Enter' && !e.shiftKey && (!isMobile || e.metaKey || e.ctrlKey)) {
       e.preventDefault();
       save();
     } else if (e.key === 'Escape') {