Prevent premature submission on IME input

tools/server/webui/src/lib/components/app/chat/ChatForm/ChatForm.svelte

@@ -26,6 +26,7 @@
 		MimeTypeImage,
 		MimeTypeText
 	} from '$lib/enums/files';
+	import { isIMEComposing } from '$lib/utils/is-ime-composing';
 
 	interface Props {
 		class?: string;
@@ -97,7 +98,7 @@
 	}
 
 	async function handleKeydown(event: KeyboardEvent) {
-		if (event.key === 'Enter' && !event.shiftKey) {
+		if (event.key === 'Enter' && !event.shiftKey && !isIMEComposing(event)) {
 			event.preventDefault();
 
 			if ((!message.trim() && uploadedFiles.length === 0) || disabled || isLoading) return;

tools/server/webui/src/lib/components/app/chat/ChatMessages/ChatMessage.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
 	import { getDeletionInfo } from '$lib/stores/chat.svelte';
 	import { copyToClipboard } from '$lib/utils/copy';
+	import { isIMEComposing } from '$lib/utils/is-ime-composing';
 	import ChatMessageAssistant from './ChatMessageAssistant.svelte';
 	import ChatMessageUser from './ChatMessageUser.svelte';
 
@@ -93,7 +94,9 @@
 	}
 
 	function handleEditKeydown(event: KeyboardEvent) {
-		if (event.key === 'Enter' && !event.shiftKey) {
+		// Check for IME composition using isComposing property and keyCode 229 (specifically for IME composition on Safari)
+		// This prevents saving edit when confirming IME word selection (e.g., Japanese/Chinese input)
+		if (event.key === 'Enter' && !event.shiftKey && !isIMEComposing(event)) {
 			event.preventDefault();
 			handleSaveEdit();
 		} else if (event.key === 'Escape') {

tools/server/webui/src/lib/utils/is-ime-composing.ts

@@ -0,0 +1,5 @@
+export function isIMEComposing(event: KeyboardEvent) {
+	// Check for IME composition using isComposing property and keyCode 229 (specifically for IME composition on Safari, which is notorious for not supporting KeyboardEvent.isComposing)
+	// This prevents form submission when confirming IME word selection (e.g., Japanese/Chinese input)
+	return event.isComposing || event.keyCode === 229;
+}