feat: add lock API config checkbox to Settings Providers tab

Adds a discoverable "Use the same configuration for all modes" checkbox
to the Providers section in Settings. This mirrors the existing lock
icon hidden inside the API Configuration popover, making it much easier
to find.

- Checkbox in Providers tab reads from cachedState and persists on save
- i18n strings added for all 18 locales
- Tests added for render and toggle+save behavior

Addresses #12237

Author: roomote

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

@@ -60,6 +60,7 @@ import {
 	StandardTooltip,
 } from "@src/components/ui"
 
+import { Checkbox } from "vscrui"
 import { Tab, TabContent, TabHeader, TabList, TabTrigger } from "../common/Tab"
 import { SetCachedStateField, SetExperimentEnabled } from "./types"
 import { SectionHeader } from "./SectionHeader"
@@ -203,6 +204,7 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 		includeCurrentTime,
 		includeCurrentCost,
 		maxGitStatusFiles,
+		lockApiConfigAcrossModes,
 	} = cachedState
 
 	const apiConfiguration = useMemo(() => cachedState.apiConfiguration ?? {}, [cachedState.apiConfiguration])
@@ -430,6 +432,7 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 			vscode.postMessage({ type: "upsertApiConfiguration", text: currentApiConfigName, apiConfiguration })
 			vscode.postMessage({ type: "telemetrySetting", text: telemetrySetting })
 			vscode.postMessage({ type: "debugSetting", bool: cachedState.debug })
+			vscode.postMessage({ type: "lockApiConfigAcrossModes", bool: !!lockApiConfigAcrossModes })
 
 			setChangeDetected(false)
 		}
@@ -766,6 +769,19 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 											})
 										}
 									/>
+									<div className="flex flex-col gap-1 mt-4 mb-2">
+										<Checkbox
+											checked={!!lockApiConfigAcrossModes}
+											onChange={(checked: boolean) =>
+												setCachedStateField("lockApiConfigAcrossModes", checked)
+											}
+											data-testid="lock-api-config-checkbox">
+											{t("settings:providers.lockApiConfigAcrossModes")}
+										</Checkbox>
+										<div className="text-sm text-vscode-descriptionForeground ml-6">
+											{t("settings:providers.lockApiConfigAcrossModesDescription")}
+										</div>
+									</div>
 									<ApiOptions
 										uriScheme={uriScheme}
 										apiConfiguration={apiConfiguration}

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

@@ -10,6 +10,20 @@ import SettingsView from "../SettingsView"
 
 vi.mock("@src/utils/vscode", () => ({ vscode: { postMessage: vi.fn() } }))
 
+vi.mock("vscrui", () => ({
+	Checkbox: ({ children, checked, onChange, "data-testid": dataTestId }: any) => (
+		<label>
+			<input
+				type="checkbox"
+				checked={checked}
+				onChange={(e) => onChange(e.target.checked)}
+				data-testid={dataTestId}
+			/>
+			{children}
+		</label>
+	),
+}))
+
 vi.mock("../ApiConfigManager", () => ({
 	__esModule: true,
 	default: ({ currentApiConfigName }: any) => (
@@ -714,3 +728,39 @@ describe("SettingsView - Duplicate Commands", () => {
 		)
 	})
 })
+
+describe("SettingsView - Lock API Config Across Modes", () => {
+	beforeEach(() => {
+		vi.clearAllMocks()
+	})
+
+	it("renders lock API config checkbox unchecked by default on the providers tab", () => {
+		const { getSettingsContent } = renderSettingsView()
+
+		const content = getSettingsContent()
+		const lockCheckbox = within(content).getByTestId("lock-api-config-checkbox")
+		expect(lockCheckbox).not.toBeChecked()
+	})
+
+	it("toggles lock API config and sends lockApiConfigAcrossModes message on save", () => {
+		const { getSettingsContent } = renderSettingsView()
+
+		const content = getSettingsContent()
+		const lockCheckbox = within(content).getByTestId("lock-api-config-checkbox")
+
+		// Enable the lock
+		fireEvent.click(lockCheckbox)
+		expect(lockCheckbox).toBeChecked()
+
+		// Click Save
+		const saveButton = screen.getByTestId("save-button")
+		fireEvent.click(saveButton)
+
+		expect(vscode.postMessage).toHaveBeenCalledWith(
+			expect.objectContaining({
+				type: "lockApiConfigAcrossModes",
+				bool: true,
+			}),
+		)
+	})
+})

webview-ui/src/i18n/locales/ca/settings.json

@@ -351,6 +351,8 @@
 		"providerDocumentation": "{{provider}} documentation",
 		"configProfile": "Configuration Profile",
 		"description": "Save different API configurations to quickly switch between providers and settings.",
+		"lockApiConfigAcrossModes": "Use the same configuration for all modes",
+		"lockApiConfigAcrossModesDescription": "When enabled, switching modes (e.g. Code, Architect, Ask) will keep the current API configuration instead of switching to a mode-specific one.",
 		"apiProvider": "API Provider",
 		"apiProviderDocs": "Provider Docs",
 		"model": "Model",