feat(core): edit icon in navigation panel (#13595)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Rename dialog now edits per-item explorer icons (emoji or custom) and
can skip name-change callbacks. Doc icon picker added to the editor with
localized "Add icon" placeholder and readonly rendering. Icon editor
supports fallbacks, trigger variants, and improved input/test-id wiring.

- **Style**
- Updated icon picker and trigger sizing and placeholder visuals;
title/icon layout adjustments.

- **Chores**
- Explorer icon storage and module added to persist and serve icons
across the app.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/core/src/modules/index.ts

@@ -27,6 +27,7 @@ import { configureDocSummaryModule } from './doc-summary';
 import { configureDocsSearchModule } from './docs-search';
 import { configureEditorModule } from './editor';
 import { configureEditorSettingModule } from './editor-setting';
+import { configureExplorerIconModule } from './explorer-icon';
 import { configureFavoriteModule } from './favorite';
 import { configureFeatureFlagModule } from './feature-flag';
 import { configureGlobalContextModule } from './global-context';
@@ -85,6 +86,7 @@ export function configureCommonModules(framework: Framework) {
   configureTelemetryModule(framework);
   configurePDFModule(framework);
   configurePeekViewModule(framework);
+  configureExplorerIconModule(framework);
   configureDocDisplayMetaModule(framework);
   configureQuickSearchModule(framework);
   configureDocsSearchModule(framework);