fix(vscode): restrict export to custom modes and validate mode field on import

Hide export button for native/built-in agents since their full
definition is not available from config overrides alone. Validate
the mode field on import against the allowed values (subagent,
primary, all) instead of blindly casting.

packages/kilo-vscode/webview-ui/src/components/settings/AgentBehaviourTab.tsx

@@ -248,7 +248,8 @@ const AgentBehaviourTab: Component = () => {
         if (typeof data.description === "string") partial.description = data.description
         if (typeof data.prompt === "string") partial.prompt = data.prompt
         if (typeof data.model === "string") partial.model = data.model
-        if (typeof data.mode === "string") partial.mode = data.mode as AgentConfig["mode"]
+        const modes = ["subagent", "primary", "all"] as const
+        if (typeof data.mode === "string" && modes.includes(data.mode)) partial.mode = data.mode
         if (typeof data.temperature === "number") partial.temperature = data.temperature
         if (typeof data.top_p === "number") partial.top_p = data.top_p
         if (typeof data.steps === "number") partial.steps = data.steps

packages/kilo-vscode/webview-ui/src/components/settings/ModeEditView.tsx

@@ -68,15 +68,15 @@ const ModeEditView: Component<Props> = (props) => {
             {language.t("settings.agentBehaviour.editMode")} — {props.name}
           </span>
         </div>
-        <div style={{ display: "flex", gap: "4px" }}>
-          <IconButton
-            size="small"
-            variant="ghost"
-            icon="download"
-            title={language.t("settings.agentBehaviour.exportMode")}
-            onClick={exportMode}
-          />
-          <Show when={!native()}>
+        <Show when={!native()}>
+          <div style={{ display: "flex", gap: "4px" }}>
+            <IconButton
+              size="small"
+              variant="ghost"
+              icon="download"
+              title={language.t("settings.agentBehaviour.exportMode")}
+              onClick={exportMode}
+            />
             <IconButton
               size="small"
               variant="ghost"
@@ -86,8 +86,8 @@ const ModeEditView: Component<Props> = (props) => {
                 if (a) props.onRemove(a)
               }}
             />
-          </Show>
-        </div>
+          </div>
+        </Show>
       </div>
 
       <Show when={native()}>