feat(tree): replace sidebar tree (react-aborist) with custom tree implementation (#2199)

* feat(tree): replace react-arborist with custom tree implementation

* feat(tree): keyboard arrow navigation between rows

* feat(emoji-picker): focus search input on open

* refactor(emoji): switch to @slidoapp/emoji-mart fork for accessibility

* feat(tree): Home/End and typeahead keyboard navigation

* feat(tree): roving tabindex and * to expand sibling subtrees

* feat(tree): Space activation and ARIA refinements

* fix(tree): move treeitem role to focusable row + aria-current

apps/client/vitest.config.ts

@@ -0,0 +1,17 @@
+import { defineConfig } from 'vitest/config';
+import react from '@vitejs/plugin-react';
+import * as path from 'path';
+
+export default defineConfig({
+  plugins: [react()],
+  resolve: {
+    alias: {
+      '@': path.resolve(__dirname, './src'),
+    },
+  },
+  test: {
+    environment: 'jsdom',
+    globals: true,
+    setupFiles: [],
+  },
+});