feat: add supportsNativeTools toggle to OpenAI-compatible custom model info

This allows users to disable native tool calling for OpenAI-compatible
models that do not properly support the OpenAI function calling format.

Users can now set supportsNativeTools: false in the custom model info
settings to fall back to XML-based tool definitions.

Closes #10477

webview-ui/src/components/settings/providers/OpenAICompatible.tsx

@@ -420,6 +420,32 @@ export const OpenAICompatible = ({
 					</div>
 				</div>
 
+				<div>
+					<div className="flex items-center gap-1">
+						<Checkbox
+							checked={apiConfiguration?.openAiCustomModelInfo?.supportsNativeTools ?? true}
+							onChange={handleInputChange("openAiCustomModelInfo", (checked) => {
+								return {
+									...(apiConfiguration?.openAiCustomModelInfo || openAiModelInfoSaneDefaults),
+									supportsNativeTools: checked,
+								}
+							})}>
+							<span className="font-medium">
+								{t("settings:providers.customModel.nativeToolCalling.label")}
+							</span>
+						</Checkbox>
+						<StandardTooltip content={t("settings:providers.customModel.nativeToolCalling.description")}>
+							<i
+								className="codicon codicon-info text-vscode-descriptionForeground"
+								style={{ fontSize: "12px" }}
+							/>
+						</StandardTooltip>
+					</div>
+					<div className="text-sm text-vscode-descriptionForeground pt-1">
+						{t("settings:providers.customModel.nativeToolCalling.description")}
+					</div>
+				</div>
+
 				<div>
 					<VSCodeTextField
 						value={

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

@@ -475,6 +475,10 @@
 				"label": "Prompt Caching",
 				"description": "Is this model capable of caching prompts?"
 			},
+			"nativeToolCalling": {
+				"label": "Native Tool Calling",
+				"description": "Enable OpenAI-style function calling for this model. Disable if the model does not support native tool calling and falls back to XML-based tool definitions."
+			},
 			"pricing": {
 				"input": {
 					"label": "Input Price",