feat(core): new theme editor poc (#7810)

packages/frontend/electron/renderer/app.tsx

@@ -8,6 +8,7 @@ import { AppFallback } from '@affine/core/components/affine/app-container';
 import { configureCommonModules } from '@affine/core/modules';
 import { configureAppTabsHeaderModule } from '@affine/core/modules/app-tabs-header';
 import { configureElectronStateStorageImpls } from '@affine/core/modules/storage';
+import { CustomThemeModifier } from '@affine/core/modules/theme-editor';
 import { configureDesktopWorkbenchModule } from '@affine/core/modules/workbench';
 import {
   configureBrowserWorkspaceFlavours,
@@ -110,6 +111,7 @@ export function App() {
         <CacheProvider value={cache}>
           <AffineContext store={getCurrentStore()}>
             <Telemetry />
+            <CustomThemeModifier />
             <DebugProvider>
               <GlobalLoading />
               <NotificationCenter />