test(emojis): consolidate picker slot tests into integration coverage

The per-slot conversion left many heavily-mocked tests that only asserted a slot
forwards an interaction to a mocked context setter — wiring, not behavior. Replace them
with real end-to-end coverage: EmojiPickerPanel.test now mocks only react-virtuoso and
drives the real nav / search / grid / preview / skin-tone slots against real context.

- Delete the CategoryNav / EmojiButton / PreviewPane / SearchInput slot tests; their
  behavior (category activation, selection, hover preview, search, ArrowDown → grid focus)
  is now asserted through the real component tree in EmojiPickerPanel.test.
- Relocate the skin-tone resolution matrix to a resolveNative test in
  EmojiPickerContext, where that logic lives now (not in EmojiButton).
- Merge duplicates (themeClassName, entry-exports, EmojiGrid a11y, SkinToneSelector
  keyboard) and drop a trivial aria-haspopup attribute check.

Emoji suite: 104 → 92 tests, 26 → 22 files; behavior coverage preserved or improved.

Author: oliverlaz

src/plugins/Emojis/__tests__/StreamEmojiPicker.test.tsx

@@ -122,14 +122,6 @@ describe('StreamEmojiPicker session state', () => {
     fireEvent.click(screen.getByText('select-rocket'));
     expect(screen.getByTestId('frequently-used').textContent).toBe('');
   });
-
-  it('marks the toggle button as opening a dialog popup', () => {
-    render(<StreamEmojiPicker />);
-    expect(screen.getByLabelText('aria/Emoji picker')).toHaveAttribute(
-      'aria-haspopup',
-      'dialog',
-    );
-  });
 });
 
 describe('StreamEmojiPicker props', () => {

src/plugins/Emojis/__tests__/entry-exports.test.ts

@@ -2,12 +2,11 @@ import * as emojis from '../index';
 import { StreamEmojiPicker } from '../StreamEmojiPicker';
 
 describe('emojis entry exports', () => {
-  it('exports both the deprecated EmojiPicker and the StreamEmojiPicker successor', () => {
+  it('exports both pickers, the compound parts, and the context hook', () => {
+    // Deprecated emoji-mart picker + its built-in successor.
     expect(typeof emojis.EmojiPicker).toBe('function');
     expect(typeof emojis.StreamEmojiPicker).toBe('function');
-  });
-
-  it('exposes the compound API + context hook', () => {
+    // Composition surface.
     expect(typeof emojis.useEmojiPickerContext).toBe('function');
     for (const part of [
       'Grid',

src/plugins/Emojis/components/__tests__/CategoryNav.test.tsx

@@ -1,8 +1,8 @@
 import React from 'react';
-import { fireEvent, render, screen } from '@testing-library/react';
+import { render, screen } from '@testing-library/react';
 
-// Capture the Virtuoso scroll callbacks so the scroll-spy behavior is testable, and
-// render every item synchronously so the non-search view's a11y tree is assertable.
+// Capture the Virtuoso scroll callbacks so scroll-spy is testable, and render items
+// synchronously so the browse view's a11y tree is assertable (jsdom has no layout).
 const { virtuoso } = vi.hoisted(() => ({
   virtuoso: {} as {
     atBottomStateChange?: (atBottom: boolean) => void;
@@ -63,7 +63,7 @@ const base = () => ({
   isSearching: false,
   resolveNative: (e: { skins: { native: string }[] }) => e.skins[0]?.native ?? '',
   scrollTarget: null,
-  searchResults: null as null | ReturnType<typeof emoji>[],
+  searchResults: null,
   selectEmoji: vi.fn(),
   setActiveCategory: vi.fn(),
 });
@@ -72,36 +72,27 @@ beforeEach(() => {
   Object.assign(ctx, base());
 });
 
-describe('EmojiGrid accessibility (non-search view)', () => {
-  beforeEach(() => {
+describe('EmojiGrid browse view', () => {
+  it('renders emojis as labeled buttons under labeled category regions, with no orphaned grid roles', () => {
     ctx.categories = [
       {
         emojis: [emoji('grinning', '😀', 'Grinning')],
         id: 'people',
         label: 'Smileys & People',
       },
     ];
-  });
-
-  it('renders emojis as accessible buttons with no orphaned grid/row/gridcell roles', () => {
     render(<EmojiGrid />);
 
-    // The review flagged row/gridcell elements with no owning grid in the virtualized
-    // view. Native button semantics avoid the invalid ARIA entirely.
+    // Native button semantics — no invalid ARIA grid/row/gridcell in the virtualized view.
     expect(screen.queryAllByRole('grid')).toHaveLength(0);
     expect(screen.queryAllByRole('row')).toHaveLength(0);
     expect(screen.queryAllByRole('gridcell')).toHaveLength(0);
-
     expect(screen.getByRole('button', { name: 'Grinning' })).toBeInTheDocument();
-  });
-
-  it('keeps emojis grouped under a labeled category region', () => {
-    render(<EmojiGrid />);
     expect(screen.getByRole('region', { name: 'Smileys & People' })).toBeInTheDocument();
   });
 });
 
-describe('EmojiGrid scroll-spy (active category tracking)', () => {
+describe('EmojiGrid scroll-spy', () => {
   beforeEach(() => {
     ctx.categories = [
       { emojis: [emoji('grinning', '😀')], id: 'people', label: 'People' },
@@ -115,7 +106,7 @@ describe('EmojiGrid scroll-spy (active category tracking)', () => {
     expect(ctx.setActiveCategory).toHaveBeenLastCalledWith('flags');
   });
 
-  it('marks the last category active at the bottom, even when a short final category never reaches the top', () => {
+  it('pins the last category active at the bottom, even when a short final category never reaches the top', () => {
     render(<EmojiGrid />);
     virtuoso.rangeChanged?.({ endIndex: 1, startIndex: 0 });
     virtuoso.atBottomStateChange?.(true);
@@ -125,14 +116,3 @@ describe('EmojiGrid scroll-spy (active category tracking)', () => {
     expect(ctx.setActiveCategory).toHaveBeenLastCalledWith('flags');
   });
 });
-
-describe('EmojiGrid search view', () => {
-  it('renders flat search results and selects through context', () => {
-    const rocket = emoji('rocket', '🚀', 'Rocket');
-    ctx.isSearching = true;
-    ctx.searchResults = [rocket];
-    render(<EmojiGrid />);
-    fireEvent.click(screen.getByRole('button', { name: 'Rocket' }));
-    expect(ctx.selectEmoji).toHaveBeenCalledWith(rocket);
-  });
-});