[BUG] Google Chat app is missing chat.messages.readonly OAuth scope

The Google Chat app currently exposes list-messages and get-message actions, but the OAuth flow does not request the chat.messages.readonly scope required to call those endpoints. As a result, every call to google_chat-list-messages or google_chat-get-message returns:

text
403 PERMISSION_DENIED
Reason: ACCESS_TOKEN_SCOPE_INSUFFICIENT
Steps to reproduce:

Connect the Google Chat app via OAuth (any account, any consent setting).

Call google_chat-list-spaces — works correctly.

Call google_chat-list-messages against any returned space ID — returns 403.

The OAuth consent screen never offers a "View your chat messages" checkbox, confirming the scope is not in the requested set. I have verified this by fully revoking access at myaccount.google.com/connections and reconnecting from scratch with each scope checkbox manually selected.

Requested fix: add https://www.googleapis.com/auth/chat.messages.readonly (and ideally chat.messages.reactions.readonly) to the Google Chat app's requested scopes so the existing read actions actually work.