Do not force the Chat panel to open by default for all users.

Proposed behavior:

New users → Chat panel opens by default

Existing users → Properties panel opens by default (or retain previous behavior)

Alternative (preferred if simpler):

Persist the last-used side panel per user (Chat or Properties) and restore on load

Problem being solved:

Current default (Chat open) introduces unnecessary friction for experienced users who primarily use the Properties panel for variable and table configuration.