* FEATURE: add composer warning when user haven't been seen in a long time
When a user creates a PM and adds a recipient that hasn't been seen in a
long time then we'll now show a warning in composer indicating that the
user hasn't been seen in a long time.
Zeitwerk simplifies working with dependencies in dev and makes it easier reloading class chains.
We no longer need to use Rails "require_dependency" anywhere and instead can just use standard
Ruby patterns to require files.
This is a far reaching change and we expect some followups here.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging