feat: show rate limiting countdown as informational message instead of error

- Create RateLimitCountdown component with informational styling
- Detect rate limiting messages in ChatRow and render new component
- Add translation key for rate limiting countdown message
- Add tests for RateLimitCountdown component

Fixes #10202

Author: roomote

webview-ui/src/components/chat/ChatRow.tsx

@@ -25,6 +25,7 @@ import { ReasoningBlock } from "./ReasoningBlock"
 import Thumbnails from "../common/Thumbnails"
 import ImageBlock from "../common/ImageBlock"
 import ErrorRow from "./ErrorRow"
+import { RateLimitCountdown } from "./RateLimitCountdown"
 
 import McpResourceRow from "../mcp/McpResourceRow"
 
@@ -1087,6 +1088,14 @@ export const ChatRowContent = ({
 						</>
 					)
 				case "api_req_retry_delayed":
+					// Check if this is user-configured rate limiting (not an API error)
+					if (message.text?.startsWith("Rate limiting for")) {
+						// Extract countdown from message text: "Rate limiting for X seconds..."
+						const rateLimitMatch = message.text.match(/Rate limiting for (\d+) seconds/)
+						const countdown = rateLimitMatch ? parseInt(rateLimitMatch[1], 10) : 0
+						return <RateLimitCountdown seconds={countdown} />
+					}
+	
 					let body = t(`chat:apiRequest.failed`)
 					let retryInfo, rawError, code, docsURL
 					if (message.text !== undefined) {

webview-ui/src/components/chat/RateLimitCountdown.tsx

@@ -0,0 +1,30 @@
+import React, { memo } from "react"
+import { useTranslation } from "react-i18next"
+import { Timer } from "lucide-react"
+
+export interface RateLimitCountdownProps {
+	seconds: number
+}
+
+/**
+ * Displays a user-configured rate limiting countdown as an informational message.
+ * This is NOT an error state - it's expected behavior based on user settings.
+ *
+ * Uses neutral/informational styling instead of error styling.
+ */
+export const RateLimitCountdown = memo(({ seconds }: RateLimitCountdownProps) => {
+	const { t } = useTranslation()
+
+	return (
+		<div className="flex items-center gap-2 text-vscode-descriptionForeground">
+			<Timer className="size-4 shrink-0" strokeWidth={1.5} />
+			<span className="text-sm">
+				{t("chat:rateLimit.countdown", { seconds, defaultValue: `Rate limiting: ${seconds}s` })}
+			</span>
+		</div>
+	)
+})
+
+RateLimitCountdown.displayName = "RateLimitCountdown"
+
+export default RateLimitCountdown

webview-ui/src/components/chat/__tests__/RateLimitCountdown.spec.tsx

@@ -0,0 +1,54 @@
+import React from "react"
+
+import { render, screen } from "@/utils/test-utils"
+
+import { RateLimitCountdown } from "../RateLimitCountdown"
+
+// Mock i18n
+vi.mock("react-i18next", () => ({
+	useTranslation: () => ({
+		t: (key: string, params?: { seconds?: number }) => {
+			if (key === "chat:rateLimit.countdown") {
+				return `Rate limiting: ${params?.seconds}s`
+			}
+			return key
+		},
+	}),
+	initReactI18next: {
+		type: "3rdParty",
+		init: vi.fn(),
+	},
+}))
+
+describe("RateLimitCountdown", () => {
+	it("renders with countdown seconds", () => {
+		render(<RateLimitCountdown seconds={5} />)
+
+		expect(screen.getByText("Rate limiting: 5s")).toBeInTheDocument()
+	})
+
+	it("renders with zero seconds", () => {
+		render(<RateLimitCountdown seconds={0} />)
+
+		expect(screen.getByText("Rate limiting: 0s")).toBeInTheDocument()
+	})
+
+	it("uses informational styling (not error styling)", () => {
+		const { container } = render(<RateLimitCountdown seconds={10} />)
+
+		// Check that the component has the expected informational styling class
+		const rootDiv = container.firstChild as HTMLElement
+		expect(rootDiv).toHaveClass("text-vscode-descriptionForeground")
+
+		// Verify it does NOT have error-related styling
+		expect(rootDiv).not.toHaveClass("text-vscode-errorForeground")
+	})
+
+	it("renders the Timer icon", () => {
+		const { container } = render(<RateLimitCountdown seconds={5} />)
+
+		// Lucide icons render as SVG elements
+		const svgIcon = container.querySelector("svg")
+		expect(svgIcon).toBeInTheDocument()
+	})
+})

webview-ui/src/i18n/locales/en/chat.json

@@ -470,5 +470,8 @@
 		"updated": "Updated the to-do list",
 		"completed": "Completed",
 		"started": "Started"
+	},
+	"rateLimit": {
+		"countdown": "Rate limiting: {{seconds}}s"
 	}
 }