fix: remove orphaned taskHeaderHighlight setting from UISettings

The taskHeaderHighlight feature was reverted on main (#11349), but the
setting toggle was re-introduced during merge without the needed
translation keys. Remove the setting block, handler, and prop since
the feature no longer exists and the toggle was not wired into the
save payload.

webview-ui/src/components/settings/SettingsView.tsx

@@ -213,7 +213,6 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 		includeCurrentCost,
 		maxGitStatusFiles,
 		showQuestionsOneByOne,
-		taskHeaderHighlightEnabled,
 	} = cachedState
 
 	const apiConfiguration = useMemo(() => cachedState.apiConfiguration ?? {}, [cachedState.apiConfiguration])
@@ -925,7 +924,6 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 								reasoningBlockCollapsed={reasoningBlockCollapsed ?? true}
 								enterBehavior={enterBehavior ?? "send"}
 								showQuestionsOneByOne={showQuestionsOneByOne ?? false}
-								taskHeaderHighlightEnabled={taskHeaderHighlightEnabled ?? false}
 								setCachedStateField={setCachedStateField}
 							/>
 						)}

webview-ui/src/components/settings/UISettings.tsx

@@ -13,7 +13,6 @@ interface UISettingsProps extends HTMLAttributes<HTMLDivElement> {
 	reasoningBlockCollapsed: boolean
 	enterBehavior: "send" | "newline"
 	showQuestionsOneByOne: boolean
-	taskHeaderHighlightEnabled: boolean
 	setCachedStateField: SetCachedStateField<keyof ExtensionStateContextType>
 }
 
@@ -21,7 +20,6 @@ export const UISettings = ({
 	reasoningBlockCollapsed,
 	enterBehavior,
 	showQuestionsOneByOne,
-	taskHeaderHighlightEnabled,
 	setCachedStateField,
 	...props
 }: UISettingsProps) => {
@@ -61,10 +59,6 @@ export const UISettings = ({
 		})
 	}
 
-	const handleTaskHeaderHighlightChange = (enabled: boolean) => {
-		setCachedStateField("taskHeaderHighlightEnabled", enabled)
-	}
-
 	return (
 		<div {...props}>
 			<SectionHeader>{t("settings:sections.ui")}</SectionHeader>
@@ -126,24 +120,6 @@ export const UISettings = ({
 							</div>
 						</div>
 					</SearchableSetting>
-
-					{/* Task Header Highlight Setting */}
-					<SearchableSetting
-						settingId="ui-task-header-highlight"
-						section="ui"
-						label={t("settings:ui.taskHeaderHighlight.label")}>
-						<div className="flex flex-col gap-1">
-							<VSCodeCheckbox
-								checked={taskHeaderHighlightEnabled}
-								onChange={(e: any) => handleTaskHeaderHighlightChange(e.target.checked)}
-								data-testid="task-header-highlight-checkbox">
-								<span className="font-medium">{t("settings:ui.taskHeaderHighlight.label")}</span>
-							</VSCodeCheckbox>
-							<div className="text-vscode-descriptionForeground text-sm ml-5 mt-1">
-								{t("settings:ui.taskHeaderHighlight.description")}
-							</div>
-						</div>
-					</SearchableSetting>
 				</div>
 			</Section>
 		</div>

webview-ui/src/components/settings/__tests__/UISettings.spec.tsx

@@ -7,7 +7,6 @@ describe("UISettings", () => {
 		reasoningBlockCollapsed: false,
 		enterBehavior: "send" as const,
 		showQuestionsOneByOne: false,
-		taskHeaderHighlightEnabled: false,
 		setCachedStateField: vi.fn(),
 	}