For spectators, the chunk of page_params that originates from
do_events_register isn’t assigned until ui_init.js. That means the
TypeScript type of page_params is mostly a lie during module load
time: reading a parameter too early silently results in undefined
rather than the declared type, with unpredictable results later on.
We want to make such an early read into an immediate runtime error,
for both users and spectators consistently, and pave the way for
runtime validation of the page_params type. As a second step, split
out the subset of fields that pertain to the entire realm.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
This is important because the "guests" value isn't one that we'd
expect anyone to pick intentionally, and in particular isn't an
available option for the similar/adjacent "email invitations" setting.
This commit adds a new module group_permission_settings.ts
which is used to define configuration options like
allow_owners_group, allow_nobody_group, etc. for group-based
settings similar to GroupPermissionSetting dataclass we have
in backend.