closes #2127 
This PR includes 

- Fixing the regression introduced in the beta release
- Adding the plus button to HomeChatInput

I will create a follow-up PR that makes the e2e test more realistic


<!-- This is an auto-generated description by cubic. -->
---
## Summary by cubic
Adds a plus actions menu to HomeChatInput for attachments and fixes the
beta regression that prevented attaching files in home chat.

- **New Features**
- Added AuxiliaryActionsMenu to HomeChatInput with an “Attach files”
submenu; hides context picker and token toggle when not needed.
- Made menu props optional (showTokenBar/toggle) and added
hideContextFilesPicker, improving reuse across inputs.

- **Bug Fixes**
- Restored file upload by handling menu item onSelect and closing the
submenu after selection; inputs reset to allow re-uploading the same
file.
- Updated the e2e test to open the menu, hover “Attach files,” upload
via the file input, and close with Escape.

<sup>Written for commit 3db5abc98c9f968cb04eb355a586209e4725be30.
Summary will update on new commits.</sup>

<!-- End of auto-generated description by cubic. -->




<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Introduces a consolidated plus “AuxiliaryActionsMenu” for file/context
actions in both chat inputs and fixes attachment menu interactions.
> 
> - Adds `AuxiliaryActionsMenu` with optional `showTokenBar/toggle`,
`showContextFilesPicker`, and `isStreaming`; disables attach submenu
while streaming and conditionally shows context picker and token toggle
> - Refactors `FileAttachmentDropdown` to render only menu items +
hidden inputs, use `onSelect` to trigger file pickers, clear input
values, and close parent via `onMenuClose`
> - Integrates the new menu into `HomeChatInput` and `ChatInput`; keeps
`ChatInputControls` and hides context picker where not needed
> - Updates e2e tests to interact with the new menu, including
attach-as-context, upload-to-codebase, and drag-and-drop flows;
standardizes snapshots and closes menus via Escape
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
6b0d1f24b069a9e9b066f8dba59a8f43af318a08. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->