refactor: move selection capture from webview to extension

- Remove selection context state management from ChatView
- Remove requestSelectionContext message type and handler
- Extension now captures selection directly in newTask and askResponse handlers
- Eliminates race condition between selection request and message send
- Simplifies architecture by removing unnecessary webview complexity

src/core/webview/webviewMessageHandler.ts

@@ -427,45 +427,46 @@ export const webviewMessageHandler = async (
 		}
 	}
 
-	switch (message.type) {
-		case "requestSelectionContext": {
-			// Get the active editor and its selection
-			const editor = vscode.window.activeTextEditor
-			if (editor && !editor.selection.isEmpty) {
-				const selection = editor.selection
-				const selectedText = editor.document.getText(selection)
-				const filePath = editor.document.uri.fsPath
+	// Helper function to capture current editor selection
+	const captureSelectionContext = ():
+		| {
+				selectedText: string
+				selectionFilePath: string
+				selectionStartLine: number
+				selectionEndLine: number
+		  }
+		| undefined => {
+		const editor = vscode.window.activeTextEditor
+		if (editor && !editor.selection.isEmpty) {
+			const selection = editor.selection
+			const selectedText = editor.document.getText(selection)
+			const filePath = editor.document.uri.fsPath
 
-				// Convert to workspace-relative path if possible
-				const workspacePath = provider.cwd
-				let relativeFilePath: string
-				if (filePath.startsWith(workspacePath)) {
-					relativeFilePath = path.relative(workspacePath, filePath)
-				} else {
-					// File is outside workspace, use absolute path
-					relativeFilePath = filePath
-				}
-
-				// VSCode uses 0-based line numbers, convert to 1-based for user-friendly display
-				const startLine = selection.start.line + 1
-				const endLine = selection.end.line + 1
-
-				// Send selection context to webview only - don't store in task
-				await provider.postMessageToWebview({
-					type: "selectionContext",
-					selectedText,
-					selectionFilePath: relativeFilePath,
-					selectionStartLine: startLine,
-					selectionEndLine: endLine,
-				})
+			// Convert to workspace-relative path if possible
+			const workspacePath = provider.cwd
+			let relativeFilePath: string
+			if (filePath.startsWith(workspacePath)) {
+				relativeFilePath = path.relative(workspacePath, filePath)
 			} else {
-				// No selection, send empty context
-				await provider.postMessageToWebview({
-					type: "selectionContext",
-				})
+				// File is outside workspace, use absolute path
+				relativeFilePath = filePath
+			}
+
+			// VSCode uses 0-based line numbers, convert to 1-based for user-friendly display
+			const startLine = selection.start.line + 1
+			const endLine = selection.end.line + 1
+
+			return {
+				selectedText,
+				selectionFilePath: relativeFilePath,
+				selectionStartLine: startLine,
+				selectionEndLine: endLine,
 			}
-			break
 		}
+		return undefined
+	}
+
+	switch (message.type) {
 		case "webviewDidLaunch":
 			// Load custom modes first
 			const customModes = await provider.customModesManager.getCustomModes()
@@ -545,19 +546,11 @@ export const webviewMessageHandler = async (
 			// agentically running promises in old instance don't affect our new
 			// task. This essentially creates a fresh slate for the new task.
 			try {
+				// Capture selection context directly when creating task
+				const selectionContext = captureSelectionContext()
+
 				await provider.createTask(message.text, message.images, undefined, {
-					selectionContext:
-						message.selectedText &&
-						message.selectionFilePath &&
-						typeof message.selectionStartLine === "number" &&
-						typeof message.selectionEndLine === "number"
-							? {
-									selectedText: message.selectedText,
-									selectionFilePath: message.selectionFilePath,
-									selectionStartLine: message.selectionStartLine,
-									selectionEndLine: message.selectionEndLine,
-								}
-							: undefined,
+					selectionContext,
 				})
 
 				// Task created successfully - notify the UI to reset
@@ -577,19 +570,9 @@ export const webviewMessageHandler = async (
 
 		case "askResponse": {
 			const task = provider.getCurrentTask()
-			// Pass selection context through to handleWebviewAskResponse
-			const selectionContext =
-				message.selectedText &&
-				message.selectionFilePath &&
-				typeof message.selectionStartLine === "number" &&
-				typeof message.selectionEndLine === "number"
-					? {
-							selectedText: message.selectedText,
-							selectionFilePath: message.selectionFilePath,
-							selectionStartLine: message.selectionStartLine,
-							selectionEndLine: message.selectionEndLine,
-						}
-					: undefined
+			// Capture selection context directly when handling response
+			const selectionContext = captureSelectionContext()
+
 			task?.handleWebviewAskResponse(message.askResponse!, message.text, message.images, selectionContext)
 			break
 		}

src/shared/ExtensionMessage.ts

@@ -128,12 +128,7 @@ export interface ExtensionMessage {
 		| "dismissedUpsells"
 		| "organizationSwitchResult"
 		| "interactionRequired"
-		| "selectionContext"
 	text?: string
-	selectedText?: string
-	selectionFilePath?: string
-	selectionStartLine?: number
-	selectionEndLine?: number
 	payload?: any // Add a generic payload for now, can refine later
 	// Checkpoint warning message
 	checkpointWarning?: {

src/shared/WebviewMessage.ts

@@ -165,12 +165,7 @@ export interface WebviewMessage {
 		| "dismissUpsell"
 		| "getDismissedUpsells"
 		| "updateSettings"
-		| "requestSelectionContext"
 	text?: string
-	selectedText?: string
-	selectionFilePath?: string
-	selectionStartLine?: number
-	selectionEndLine?: number
 	editedMessageContent?: string
 	tab?: "settings" | "history" | "mcp" | "modes" | "chat" | "marketplace" | "cloud"
 	disabled?: boolean

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

@@ -134,13 +134,6 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 	const textAreaRef = useRef<HTMLTextAreaElement>(null)
 	const [sendingDisabled, setSendingDisabled] = useState(false)
 	const [selectedImages, setSelectedImages] = useState<string[]>([])
-	const [selectionContext, setSelectionContext] = useState<{
-		selectedText?: string
-		selectionFilePath?: string
-		selectionStartLine?: number
-		selectionEndLine?: number
-	} | null>(null)
-
 	// We need to hold on to the ask because useEffect > lastMessage will always
 	// let us know when an ask comes in and handle it, but by the time
 	// handleMessage is called, the last message might not be the ask anymore
@@ -568,16 +561,8 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 				// Mark that user has responded - this prevents any pending auto-approvals.
 				userRespondedRef.current = true
 
-				// Request fresh selection context before sending
-				vscode.postMessage({ type: "requestSelectionContext" })
-
 				if (messagesRef.current.length === 0) {
-					vscode.postMessage({
-						type: "newTask",
-						text,
-						images,
-						...(selectionContext || {}),
-					})
+					vscode.postMessage({ type: "newTask", text, images })
 				} else if (clineAskRef.current) {
 					if (clineAskRef.current === "followup") {
 						markFollowUpAsAnswered()
@@ -602,26 +587,19 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 								askResponse: "messageResponse",
 								text,
 								images,
-								...(selectionContext || {}),
 							})
 							break
 						// There is no other case that a textfield should be enabled.
 					}
 				} else {
 					// This is a new message in an ongoing task.
-					vscode.postMessage({
-						type: "askResponse",
-						askResponse: "messageResponse",
-						text,
-						images,
-						...(selectionContext || {}),
-					})
+					vscode.postMessage({ type: "askResponse", askResponse: "messageResponse", text, images })
 				}
 
 				handleChatReset()
 			}
 		},
-		[handleChatReset, markFollowUpAsAnswered, sendingDisabled, isStreaming, messageQueue.length, selectionContext], // messagesRef and clineAskRef are stable
+		[handleChatReset, markFollowUpAsAnswered, sendingDisabled, isStreaming, messageQueue.length], // messagesRef and clineAskRef are stable
 	)
 
 	const handleSetChatBoxMessage = useCallback(
@@ -764,15 +742,6 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 							break
 					}
 					break
-				case "selectionContext":
-					// Update selection context when received from extension
-					setSelectionContext({
-						selectedText: message.selectedText,
-						selectionFilePath: message.selectionFilePath,
-						selectionStartLine: message.selectionStartLine,
-						selectionEndLine: message.selectionEndLine,
-					})
-					break
 				case "selectedImages":
 					// Only handle selectedImages if it's not for editing context
 					// When context is "edit", ChatRow will handle the images