feat(sidebar): rename demoGroup to demoGroups, add multi-group support, search by group name, and context menu group navigation

readme.hints.md

@@ -62,6 +62,33 @@ Section names are URL-encoded. Legacy routes (`element`/`page` as section name)
 
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+## Element Demo Groups (2026-01-27)
+
+### Overview
+Elements can declare `demoGroups` (renamed from `demoGroup`) as a static property to appear grouped in the sidebar. Supports `string | string[]` — elements with an array appear in multiple groups simultaneously.
+
+### Usage
+```typescript
+// Single group
+public static demoGroups = 'Buttons';
+
+// Multiple groups — element appears in both
+public static demoGroups = ['Buttons', 'Form Controls'];
+```
+
+### Features
+- Search matches group names (searching "Buttons" shows all elements in that group)
+- Groups sorted alphabetically by group name
+- Multi-group elements show `library_books` icon instead of `featured_video`
+- Context menu shows "Show in Group:" with clickable group entries that scroll to and highlight the group
+- `data-group` attribute on `.item-group` containers for DOM querying
+
+### Files Changed
+- `ts_web/elements/wcc-sidebar.ts` — grouping logic, search filter, sort key, icon, context menu, scrollToGroup
+- `test/elements/test-button-*.ts`, `test/elements/test-input-*.ts` — renamed `demoGroup` → `demoGroups`
+
+---
+
 ## UI Redesign with Shadcn-like Styles (2025-06-27)
 
 ### Changes Made