feat: add delete button next to copy button for AI messages

- Added delete button in Markdown component alongside copy button
- Buttons appear on hover with same styling as copy button
- Pass messageTs prop through ChatRow to enable deletion
- Follows existing UI pattern for user message deletion

Addresses #9035

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

@@ -1061,7 +1061,7 @@ export const ChatRowContent = ({
 								<span style={{ fontWeight: "bold" }}>{t("chat:text.rooSaid")}</span>
 							</div>
 							<div className="pl-6">
-								<Markdown markdown={message.text} partial={message.partial} />
+								<Markdown markdown={message.text} partial={message.partial} messageTs={message.ts} />
 								{message.images && message.images.length > 0 && (
 									<div style={{ marginTop: "10px" }}>
 										{message.images.map((image, index) => (
@@ -1170,7 +1170,7 @@ export const ChatRowContent = ({
 								{title}
 							</div>
 							<div className="border-l border-green-600/30 ml-2 pl-4 pb-1">
-								<Markdown markdown={message.text} />
+								<Markdown markdown={message.text} messageTs={message.ts} />
 							</div>
 						</>
 					)
@@ -1324,7 +1324,7 @@ export const ChatRowContent = ({
 								</div>
 							)}
 							<div style={{ paddingTop: 10 }}>
-								<Markdown markdown={message.text} partial={message.partial} />
+								<Markdown markdown={message.text} partial={message.partial} messageTs={message.ts} />
 							</div>
 						</>
 					)
@@ -1410,7 +1410,11 @@ export const ChatRowContent = ({
 									{title}
 								</div>
 								<div style={{ color: "var(--vscode-charts-green)", paddingTop: 10 }}>
-									<Markdown markdown={message.text} partial={message.partial} />
+									<Markdown
+										markdown={message.text}
+										partial={message.partial}
+										messageTs={message.ts}
+									/>
 								</div>
 							</div>
 						)
@@ -1429,6 +1433,7 @@ export const ChatRowContent = ({
 							<div className="flex flex-col gap-2 ml-6">
 								<Markdown
 									markdown={message.partial === true ? message?.text : followUpData?.question}
+									messageTs={message.ts}
 								/>
 								<FollowUpSuggest
 									suggestions={followUpData?.suggest}

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

@@ -3,15 +3,31 @@ import { VSCodeButton } from "@vscode/webview-ui-toolkit/react"
 
 import { useCopyToClipboard } from "@src/utils/clipboard"
 import { StandardTooltip } from "@src/components/ui"
+import { vscode } from "@src/utils/vscode"
 
 import MarkdownBlock from "../common/MarkdownBlock"
 
-export const Markdown = memo(({ markdown, partial }: { markdown?: string; partial?: boolean }) => {
+interface MarkdownProps {
+	markdown?: string
+	partial?: boolean
+	messageTs?: number
+	onDeleteMessage?: () => void
+}
+
+export const Markdown = memo(({ markdown, partial, messageTs, onDeleteMessage }: MarkdownProps) => {
 	const [isHovering, setIsHovering] = useState(false)
 
 	// Shorter feedback duration for copy button flash.
 	const { copyWithFeedback } = useCopyToClipboard(200)
 
+	const handleDelete = () => {
+		if (onDeleteMessage) {
+			onDeleteMessage()
+		} else if (messageTs) {
+			vscode.postMessage({ type: "deleteMessage", value: messageTs })
+		}
+	}
+
 	if (!markdown || markdown.length === 0) {
 		return null
 	}
@@ -33,6 +49,8 @@ export const Markdown = memo(({ markdown, partial }: { markdown?: string; partia
 						opacity: 0,
 						animation: "fadeIn 0.2s ease-in-out forwards",
 						borderRadius: "4px",
+						display: "flex",
+						gap: "4px",
 					}}>
 					<style>{`@keyframes fadeIn { from { opacity: 0; } to { opacity: 1.0; } }`}</style>
 					<StandardTooltip content="Copy as markdown">
@@ -60,6 +78,22 @@ export const Markdown = memo(({ markdown, partial }: { markdown?: string; partia
 							<span className="codicon codicon-copy" />
 						</VSCodeButton>
 					</StandardTooltip>
+					{(messageTs || onDeleteMessage) && (
+						<StandardTooltip content="Delete message">
+							<VSCodeButton
+								className="delete-button"
+								appearance="icon"
+								style={{
+									height: "24px",
+									border: "none",
+									background: "var(--vscode-editor-background)",
+									transition: "background 0.2s ease-in-out",
+								}}
+								onClick={handleDelete}>
+								<span className="codicon codicon-trash" />
+							</VSCodeButton>
+						</StandardTooltip>
+					)}
 				</div>
 			)}
 		</div>