feat: add lock API config toggle to Settings providers tab (#12237)

Adds a "Use the same API configuration for all modes" checkbox to the
Providers section in Settings, making the existing lockApiConfigAcrossModes
feature discoverable without needing to find the small lock icon inside
the API Configuration popover.

- Adds VSCodeCheckbox to SettingsView providers tab bound to cachedState
- Sends lockApiConfigAcrossModes message on save (same handler as popover)
- Adds i18n strings for the label and description
- Adds test coverage for rendering, toggling, and save behavior

Author: roomote

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

@@ -39,6 +39,8 @@ import {
 	ImageGenerationProvider,
 } from "@roo-code/types"
 
+import { VSCodeCheckbox } from "@vscode/webview-ui-toolkit/react"
+
 import { vscode } from "@src/utils/vscode"
 import { cn } from "@src/lib/utils"
 import { useAppTranslation } from "@src/i18n/TranslationContext"
@@ -203,6 +205,7 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 		includeCurrentTime,
 		includeCurrentCost,
 		maxGitStatusFiles,
+		lockApiConfigAcrossModes,
 	} = cachedState
 
 	const apiConfiguration = useMemo(() => cachedState.apiConfiguration ?? {}, [cachedState.apiConfiguration])
@@ -430,6 +433,7 @@ 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 ?? false })
 
 			setChangeDetected(false)
 		}
@@ -766,6 +770,21 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 											})
 										}
 									/>
+									<div className="mt-2 mb-3">
+										<VSCodeCheckbox
+											checked={lockApiConfigAcrossModes ?? false}
+											onChange={(e: any) =>
+												setCachedStateField("lockApiConfigAcrossModes", e.target.checked)
+											}
+											data-testid="lock-api-config-across-modes-checkbox">
+											<span className="font-medium">
+												{t("settings:providers.lockApiConfigAcrossModes")}
+											</span>
+										</VSCodeCheckbox>
+										<div className="text-vscode-descriptionForeground text-sm mt-1 ml-5">
+											{t("settings:providers.lockApiConfigAcrossModesDescription")}
+										</div>
+									</div>
 									<ApiOptions
 										uriScheme={uriScheme}
 										apiConfiguration={apiConfiguration}