set the :model to "install" when doing :install activity.  set the :model_id to the `user_id` on :user-joined activity entries.  and make the proces-activity-event public so that we can use it for testing easily.

use null instead of empty array as default state for cards and activity lists so that we know when they are unset and thus are still loading.

include a :card-create event in our view logging because realistically the user is always looking at the card they are creating.

reorganize things a little and simplify the rendering code a bit where possible.  also remove react components that weren't really needed.

fix issue where previous table listing was being displayed momentarily even after a new database is chosen.

a little more work to get color assignment working in the case where we have more users than colors.

support more card filtering options such as by database, plus make it possible to indicate and clear the table filter choice.