The V3b run on .21 died with `open portal capturer: timed out waiting for the ScreenCast portal` —
a GNOME consent dialog nobody answered — and the kit reported "arm A is not the in-process arm".
That is false: the arm was constructed correctly (`PUNKTFUNK_ENCODE_WORKER=off` is right there in
the captured env header), it simply never reached encoder-open, so the line the assert looks for
could not exist. A red that points at the wrong thing costs the same debugging time as a green that
hides a real one.
`spike_failure_reason` now runs BEFORE any arm-identity assert in v2, v3a and v3b, and names the
actual cause: the portal timeout gets its own message saying the dialog appears on the HOST's own
screen and cannot be answered from inside a stream — which is precisely the situation that produced
this failure, since the operator was watching the box through a game session at the time.
Falls back to the first ERROR line, then to "no PUNKTFUNK_PERF window at all", so a spike that dies
some other way still reports that rather than a misattribution.
enricobuehler
854b14a52e