refactor: remove dead MessageMenu and finish useAudioPlayer rename (#3556)

## Summary

Two small V9 cleanups that finish incomplete refactors.

### 1. Remove dead `MessageMenu` component

`MessageMenu` was left in the v9 public surface but the overlay path no
longer renders it. The source file carried an explicit `// TODO: V9:
Either remove this or refactor it, as its logic is offloaded to other
components now` note from the original author. Customers who customized
`MessageMenu` in v8 had an override that silently no-op'd in v9 — a type
error is more helpful.

- Deletes `package/src/components/MessageMenu/MessageMenu.tsx`
- Drops the `MessageMenu` import + `DEFAULT_COMPONENTS` entry in
`defaultComponents.ts`
- Drops the `./MessageMenu/MessageMenu` re-export from the components
barrel
- The surrounding `MessageMenu/` folder stays — `MessageActionList`,
`MessageActionListItem`, `MessageReactionPicker`, and
`MessageUserReactions` are the live replacements and remain overridable
via `WithComponents`.

### 2. Finish `useAudioPlayerControl` → `useAudioPlayer` rename

The v9 docs already document `useAudioPlayerControl → useAudioPlayer`,
and `src/hooks/useAudioPlayer.ts` was added. But the barrel still
exported `useAudioPlayerControl` from the byte-identical older file, so
the rename never actually shipped. Internal callers (`AudioAttachment`,
`AudioRecordingPreview`) were already importing the new name directly —
only the barrel was stale.

- `src/hooks/index.ts` barrel now exports `./useAudioPlayer`
- `src/hooks/useAudioPlayerControl.ts` deleted (byte-identical
duplicate)
- No internal call sites needed updating — they already used the new
name

## Test plan

- [x] `yarn tsc --noEmit` — passes
- [x] `TZ=UTC yarn jest src/components/MessageMenu/__tests__/` — 30/30
tests pass
- [ ] Smoke test: mount sample app, long-press a message to open the
overlay, confirm reactions + actions render (unchanged behavior;
MessageMenu wasn't rendering anyway)
- [ ] Smoke test: play back an audio attachment (exercises
`useAudioPlayer`)

## Related docs updates

The v8→v9 human migration guide needs follow-up edits in `docs-content`
(separate PR) to reflect:
- `MessageMenu` removed (not "still exported but inert")
- `useAudioPlayerControl → useAudioPlayer` is now a real rename

Author: oliverlaz

package/src/components/MessageMenu/MessageMenu.tsx

@@ -163,7 +163,6 @@ export * from './MessageList/hooks/useMessageGroupStyles';
 
 export * from './MessageMenu/MessageActionList';
 export * from './MessageMenu/MessageActionListItem';
-export * from './MessageMenu/MessageMenu';
 export * from './MessageMenu/MessageUserReactions';
 export * from './MessageMenu/MessageUserReactionsAvatar';
 export * from './MessageMenu/MessageReactionPicker';

package/src/components/index.ts

@@ -123,7 +123,6 @@ import { TypingIndicatorContainer } from '../../components/MessageList/TypingInd
 import { UnreadMessagesNotification } from '../../components/MessageList/UnreadMessagesNotification';
 import { MessageActionList } from '../../components/MessageMenu/MessageActionList';
 import { MessageActionListItem } from '../../components/MessageMenu/MessageActionListItem';
-import { MessageMenu } from '../../components/MessageMenu/MessageMenu';
 import { MessageReactionPicker } from '../../components/MessageMenu/MessageReactionPicker';
 import { MessageUserReactions } from '../../components/MessageMenu/MessageUserReactions';
 import { MessageUserReactionsAvatar } from '../../components/MessageMenu/MessageUserReactionsAvatar';
@@ -226,7 +225,6 @@ const components = {
   MessageInputTrailingView,
   MessageItemView,
   MessageList,
-  MessageMenu,
   MessagePinnedHeader,
   MessageReactionPicker,
   MessageReminderHeader,

package/src/contexts/componentsContext/defaultComponents.ts

@@ -12,7 +12,7 @@ export * from './useClientNotifications';
 export * from './useInAppNotificationsState';
 export * from './usePortalSettledCallback';
 export * from './useRAFCoalescedValue';
-export * from './useAudioPlayerControl';
+export * from './useAudioPlayer';
 export * from './useAttachmentPickerState';
 export * from './messagePreview/useMessageDeliveryStatus';
 export * from './messagePreview/useGroupedAttachments';