Add instance experimental setting for isolated workspaces

Introduce a singleton instance_settings store and experimental settings API, add the Experimental instance settings page, and gate execution workspace behavior behind the new enableIsolatedWorkspaces flag.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/api/instanceSettings.ts

@@ -0,0 +1,12 @@
+import type {
+  InstanceExperimentalSettings,
+  PatchInstanceExperimentalSettings,
+} from "@paperclipai/shared";
+import { api } from "./client";
+
+export const instanceSettingsApi = {
+  getExperimental: () =>
+    api.get<InstanceExperimentalSettings>("/instance/settings/experimental"),
+  updateExperimental: (patch: PatchInstanceExperimentalSettings) =>
+    api.patch<InstanceExperimentalSettings>("/instance/settings/experimental", patch),
+};