Note: This involves adding presence info of unknown users to the
presence data.
With some small tweaks, we can just add the info to the presence data
structures, just making sure the buddy list correctly skips those
entries and that we redraw the user in the case where the user creation
event arrives after the presence polling loop.
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>
