Wait out the topic load in the card release test
The main run for a77129ce failed gates (browser 1/3) on "clicking an already selected problem card releases manual selection", with the released card still selected after Enter. I could not reproduce it locally, not 15 plain runs, not under 100x CPU throttling, not with 8 runs in parallel, so the exact interleaving is not established. The only asynchronous step between opening the picker and pressing Enter is the topic load, which reapplies every filter when it lands. The test now opens the picker through openTopicFilter (which waits for that load), asserts the card holds focus before Enter, and waits for the selection to change before reading it, so a future failure says whether the key missed the button or the release did not run.
An earlier revision of this PR pinned Math.random on the theory that the redraw could land on the released card again. That was wrong: with no reports the release restores the default Medium level and the Easy card is not eligible whatever the roll, so the pin is removed.
The test passes 10 of 10 runs, and fails with the notStrictEqual assertion when the release branch in web/app.js is disabled. scripts/indent.sh --check and ESLint are clean. I did not run the full scripts/test.sh.