Fix Enter handling during IME composition

web/src/components/canvas/canvas-resource-mention-textarea.tsx

@@ -4,6 +4,7 @@ import { createPortal } from "react-dom";
 import { FileText, Image as ImageIcon, Music2, Video } from "lucide-react";
 
 import { canvasThemes } from "@/lib/canvas-theme";
+import { isImeComposing, isPlainEnterKey } from "@/lib/keyboard-event";
 import { useThemeStore } from "@/stores/use-theme-store";
 import type { CanvasResourceReference } from "@/lib/canvas/canvas-resource-references";
 
@@ -131,6 +132,10 @@ export const CanvasResourceMentionTextarea = forwardRef<HTMLTextAreaElement, Pro
                     props.onPointerUp?.(event);
                 }}
                 onKeyDown={(event) => {
+                    if (isImeComposing(event)) {
+                        onKeyDown?.(event);
+                        return;
+                    }
                     if (mention && candidates.length) {
                         if (event.key === "ArrowDown") {
                             event.preventDefault();
@@ -153,7 +158,7 @@ export const CanvasResourceMentionTextarea = forwardRef<HTMLTextAreaElement, Pro
                             return;
                         }
                     }
-                    if (event.key === "Enter" && onSubmit && !event.ctrlKey && !event.metaKey && !event.shiftKey) {
+                    if (isPlainEnterKey(event) && onSubmit) {
                         event.preventDefault();
                         onSubmit();
                         return;