fix: start plugins when the sign-in races the first plugin start

lib/__tests__/plugin-store.test.ts

@@ -287,6 +287,20 @@ describe('usePluginStore', () => {
       expect(usePluginStore.getState().initialized).toBe(true);
     });
 
+    it('starts the plugins when a call made after the sign-in joined the signed-out one', async () => {
+      const { loadPlugin } = await import('@/lib/plugin-loader');
+      let answer!: (r: unknown) => void;
+      mocks.apiFetch.mockImplementationOnce(() => new Promise((r) => { answer = r; }));
+
+      const beforeSignIn = usePluginStore.getState().initializePlugins();
+      const afterSignIn = usePluginStore.getState().initializePlugins();
+      answer({ ok: false, status: 401, json: async () => ({}) });
+      await Promise.all([beforeSignIn, afterSignIn]);
+
+      expect(loadPlugin).toHaveBeenCalledWith(expect.objectContaining({ id: 'managed-plugin' }));
+      expect(usePluginStore.getState().initialized).toBe(true);
+    });
+
     it('keeps the record when the download fails so the error can surface at load time', async () => {
       usePluginStore.setState({ plugins: [syncedRecord()] });
       mocks.downloadManagedBundle.mockRejectedValue(new Error('Could not download the bundle (HTTP 503)'));

stores/plugin-store.ts

@@ -317,7 +317,11 @@ export const usePluginStore = create<PluginStoreState>()(
         if (get().initialized) return;
 
         if (pluginInitializationPromise) {
-          await pluginInitializationPromise;
+          const joined = pluginInitializationPromise;
+          await joined;
+          // The run this joined may have ended signed out (it started before
+          // the sign-in); then this call starts the plugins itself.
+          if (!get().initialized && pluginInitializationPromise !== joined) await get().initializePlugins();
           return;
         }