feat(plugins): load activation scope from plugin manifest

Plugins can now declare activationScope ("app" | "project") in their
manifest; loader/runtime honor it to defer activation of project-scoped
plugins until a project is focused instead of activating everything at
app bootstrap. Bumps sdk/IdeaSDK to the commit that adds the field.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/features/plugins/PluginLayoutCellView.test.tsx

@@ -73,7 +73,7 @@ function renderCell(
   const gateways: Gateways = createMockGateways();
   return render(
     <DIProvider gateways={gateways}>
-      <PluginRuntimeProvider value={{ registry, failures: [], loading: false }}>
+      <PluginRuntimeProvider value={{ registry, failures: [], pending: [], loading: false }}>
         <PluginLayoutCellView
           projectId="proj-1"
           cell={props.cell ?? cell()}