[ew] chat shown when disabled if user lacks read permits to config

Need to investigate this one more to say for sure what happened and why, was shown to me once rather quickly, but the scenarios was:

- org level config set `ew.disableChat=true`
- user has no org level permissions granted
- user has site level permissions
- `/org/site/ + **` = write
- nothing granted/denied for `/org/site/CONFIG`
- chat is shown

Expectation is since it's in org level config with no site level override, chat shouldn't be shown.

No files, tests, or entry points are named. Start by reproducing the listed org-level ew.disableChat=true and site-level permission scenario, then trace how the configuration and permission checks determine chat visibility. Done means chat is hidden when the user lacks org-level permissions and has no site-level CONFIG override.

Written by the indexing model from the issue text.