fix: remove queue message button and clear localStorage draft on submit (#22615)

Fixes two bugs in the agents chat input:

1. **Remove queue message button next to stop button** — The send button
(which showed a ListPlusIcon during streaming) is now hidden when
streaming and not editing a queued message. Messages are still queued
via Enter key; only the visual button is removed. The stop button
remains.

2. **Clear localStorage draft on submit** — The `agents.empty-input`
localStorage key is now cleared synchronously in `handleSend` before the
async `onCreateChat` call. Previously, the draft was only cleared inside
the async `handleCreateChat` after `mutateAsync` resolved, allowing
Lexical editor change events to re-persist the draft during the async
gap.

site/src/pages/AgentsPage/AgentChatInput.tsx

@@ -13,13 +13,7 @@ import {
 	TooltipContent,
 	TooltipTrigger,
 } from "components/Tooltip/Tooltip";
-import {
-	ArrowUpIcon,
-	ListPlusIcon,
-	Loader2Icon,
-	Square,
-	XIcon,
-} from "lucide-react";
+import { ArrowUpIcon, Loader2Icon, Square, XIcon } from "lucide-react";
 import { memo, type ReactNode, useCallback, useRef, useState } from "react";
 import { cn } from "utils/cn";
 import { formatProviderLabel } from "./modelOptions";
@@ -317,8 +311,7 @@ export const AgentChatInput = memo<AgentChatInputProps>(
 			}
 		};
 
-		const sendButtonLabel =
-			isStreaming && editingQueuedMessageID === null ? "Queue message" : "Send";
+		const sendButtonLabel = editingQueuedMessageID !== null ? "Save" : "Send";
 
 		const content = (
 			<div className="mx-auto w-full max-w-3xl pb-4">
@@ -430,22 +423,22 @@ export const AgentChatInput = memo<AgentChatInputProps>(
 									<span className="sr-only">Stop</span>
 								</Button>
 							)}
-							<Button
-								size="icon"
-								variant="default"
-								className="size-7 rounded-full transition-colors [&>svg]:!size-6 flex items-center justify-center"
-								onClick={handleSubmit}
-								disabled={!canSend}
-							>
-								{isLoading ? (
-									<Loader2Icon className="animate-spin" />
-								) : isStreaming && editingQueuedMessageID === null ? (
-									<ListPlusIcon />
-								) : (
-									<ArrowUpIcon />
-								)}
-								<span className="sr-only">{sendButtonLabel}</span>
-							</Button>
+							{!(isStreaming && editingQueuedMessageID === null) && (
+								<Button
+									size="icon"
+									variant="default"
+									className="size-7 rounded-full transition-colors [&>svg]:!size-6 flex items-center justify-center"
+									onClick={handleSubmit}
+									disabled={!canSend}
+								>
+									{isLoading ? (
+										<Loader2Icon className="animate-spin" />
+									) : (
+										<ArrowUpIcon />
+									)}
+									<span className="sr-only">{sendButtonLabel}</span>
+								</Button>
+							)}
 						</div>
 					</div>
 					{inputStatusText && (

site/src/pages/AgentsPage/AgentsPage.tsx

@@ -814,6 +814,10 @@ export const AgentsEmptyState: FC<AgentsEmptyStateProps> = ({
 
 	const handleSend = useCallback(
 		(message: string) => {
+			// Clear the draft synchronously before the async
+			// onCreateChat call so that editor change events
+			// firing during the async gap cannot re-persist it.
+			localStorage.removeItem(emptyInputStorageKey);
 			void onCreateChat({
 				message,
 				workspaceId: selectedWorkspaceIdRef.current ?? undefined,