
            /* ── ONE card, and one session ────────────────────────────
               The check that proves round forty-eight landed rather than
               doubled. The card moved from a hand-built MediaStyle
               notification over a MediaSessionCompat to media3, which posts
               and owns the notification itself — and the way THAT goes wrong
               is not a crash and not a missing card but two of them: two
               notifications on the `playback` channel, two records in
               `dumpsys media_session`, a stale duplicate in the shade and
               media buttons arriving at whichever component the system
               picked. Nothing above this line can tell one card from two:
               `media-card` passes on the first `playback` record it finds.

               `shadeNotice()` already returns every channel our package has
               live, joined with `|`, so counting the `playback` entries is
               the whole test — and it reads the dump `media-card` just
               read, so it costs nothing and cannot disagree with the line
               above it. */
            const cards = cardNote.shadeChans.split("|").filter((c) => c === "playback").length;
            const oneCard = cards === 1;
            if (!oneCard) problems.push("EXPECT one-card " + JSON.stringify({ cards, chans: cardNote.shadeChans }));
            console.log((oneCard ? "  ok  " : " FAIL ") + "one-card".padEnd(16) + " " + JSON.stringify({ cards }));

            /* The same question of the system's own session list, and it
               FAILS ONLY ON MORE THAN ONE. `dumpsys media_session`'s shape
               is the one thing in this block that has never been held
               against a real dump, so a count of zero means "I could not
               read it", not "there is no session" — `media-session`, two
               checks up, is what asserts that there IS one. */
            const oneSession = !(sess.sessions > 1);
            if (!oneSession) problems.push("EXPECT one-session " + JSON.stringify(sess));
            console.log((oneSession ? "  ok  " : " FAIL ") + "one-session".padEnd(16) + " " + JSON.stringify({ sessions: sess.sessions }));

            /* and the plumbing underneath it, read while something is
               playing, printed and never failed — see mediaPlumbing() */
            console.log("  --  " + "media-plumbing".padEnd(16) + " " + JSON.stringify(mediaPlumbing()) + "  (advisory: prints, never fails)");
