forgetest: the jog witness judged over the sequence, as the sampler can see it

On the bench the head accelerometer's sysfs read lands two or three
samples in a one-second jog leg, and two samples on the constant-velocity
stretch read near idle with the head in full flight: the accelerometer
sees the ramps, not the travel. The first unattended queue on dev image
20260822204234 failed motion.jog-roundtrip on that (2 of 8 legs judged)
with the head plainly moving where a ramp was caught (p2p 3019, 1330,
1698, 1663). The verdict is now over the sequence: p2p across all the
legs at or above the liveness threshold, and motion on at least two
distinct legs (one jolt is not a gantry moving on every jog); the
sampler must have landed samples at all. Rerun: p2p 2897 over 17
samples, motion on 3 legs, PASS; the whole unattended queue passed (15,
then 9 re-required by the module hash) on that image.

camera.snapshot's PASS line names the half-res frame it compared (the
full-res size had been printed in its place). AccelSampler gets host
tests over a fake iio tree.

forgetest/forgetest/suite/camera.py

@@ -111,7 +111,8 @@ def snapshot(ctx):
     st, body = fc.get("/cam/status")
     ev["cam_status_after"] = body
     ctx.log("cam status after: %s", body)
-    ctx.log("PASS: snapshot %d bytes, %d with the lamp off, stream %s", len(data), len(dark), ctype)
+    ctx.log("PASS: half-res snapshot %d bytes, %d with the lamp off; full-res %d; stream %s",
+            ev["snapshot_bytes"], len(dark), len(data), ctype)
 
 
 @test("camera.sensor-profile", title="Camera geometry follows the fitted sensor", subsystem="camera",