Client text no longer lags behind the server

Every user-visible string is written once, on the server. The JavaScript clients carry a copy of that text so they can put words on screen without waiting for a round trip. A check compares the two and fails if they ever disagree.

The check only ran when someone edited the client. A string added on the server alone changed nothing under the client folder, so the check never ran, and the copy silently fell behind — by several dozen strings, including a sentence that had been reworded on the server and never updated in the copy. Nothing warned about it, because the one thing that would have warned was the thing that never ran. It went unnoticed long enough to happen three separate times.

The check now also runs when the server's text changes, so the two are compared whenever either side moves. The change that introduces a gap is the one that has to close it, instead of the gap being discovered later by whoever happens to touch the client next — which, until now, is how every one of these was found.

The same blind spot applied to the checks that keep the clients' control set and wire format in step with the server. Those run on both sides now too, and a further check fails if a client ever starts reading a server file that this arrangement does not yet cover.