setup.focus: the test's own sysfs reads go on record however the burn ends, and their tube-current check has a case

emission_seen, the two peaks the test reads from sysfs at every poll
and the count of polls that read both, was written inside emission_ok
after the three checks of the burn's result. A burn the daemon reports
dark fails at the first of them (Context.check raises), and a burn that
ends in a wizard error, a timeout or an abort never reaches emission_ok.
On each of those paths the record kept the daemon's word alone, where
the test's own reading is the one worth comparing with it. burn() now
records emission_seen, and logs it, in the finally of its run_check, so
it is on record however the burn ends. emission_ok keeps its checks, in
their order.

The check that the tube current read over HV_ON from here had no case
that could fail it: the one negative case reads both attributes at 0
and stops at the LASER_ON check, which comes first. A new case reads
the LASER_ON count nonzero and the tube current at 0, and fails on the
tube current.

Proof: tests/test_setup_burns.py, the Unit tests step of
forgetest-ci.yml (python -B -m unittest discover -s tests), 23 tests OK
on Windows with python 3.14 and on Ubuntu 24.04 with python 3.12, with
tests/test_setup_dark.py (20 OK):
test_a_burn_whose_tube_current_the_test_never_saw_rise_fails
(cnc/laser_on_sampled 118, pic/hv_current 0: Failed "the tube current
never read over 30 from here", the settings as found);
test_a_dark_burn_fails_and_still_restores finds emission_seen at 118
and 431 beside the dark result; the aborted burn's record carries
emission_seen too. run_test keeps the Run of a test that fails.
Negative controls on scratch copies: the tube-current check made
vacuous (True or ...) fails the new case (Failed not raised);
setup_burns.py as it was fails the dark case (no emission_seen) and the
aborted case. pyflakes reports no undefined name.

Acceptance: setup.focus's fingerprint moves (setup_burns.py's shared
text); no other test moves (source_sha compared before and after).
Against the campaign this series already needs, that adds no run:
850498f moved all 43 once.

forgetest/tests/test_setup_burns.py

@@ -314,7 +314,7 @@ class BurnRunTests(unittest.TestCase):
 
     def run_test(self, tid):
         t = catalog.load_suite()[tid]
-        run = Run("test", t.id, t.title)
+        run = self.run = Run("test", t.id, t.title)     # kept for a run that fails
         run.unattended = True           # the ready gate passes; the arm cue is a notice
         t.fn(Context(run, None, t))
         return run
@@ -434,6 +434,9 @@ class BurnRunTests(unittest.TestCase):
         with self.assertRaises(Failed) as cm:
             self.run_test("setup.focus")
         self.assertIn("the tube current never rose", str(cm.exception))
+        # what the test read itself is on record beside the daemon's word
+        seen = self.run.evidence["emission_seen"]
+        self.assertEqual((seen["laser_on_max"], seen["hv_max"]), (118, 431))
         self.assert_found()
 
     def test_a_head_off_its_home_fails_before_any_start(self):
@@ -469,6 +472,15 @@ class BurnRunTests(unittest.TestCase):
         self.assert_found()
         self.assert_restarted_on_found()
 
+    def test_a_burn_whose_tube_current_the_test_never_saw_rise_fails(self):
+        # The LASER_ON count read nonzero from here, and the tube current
+        # never left zero: the second witness is judged on its own reads.
+        self.plant("pic/hv_current", "0")
+        with self.assertRaises(Failed) as cm:
+            self.run_test("setup.focus")
+        self.assertIn("tube current never read over %d from here" % setup_burns.HV_ON, str(cm.exception))
+        self.assert_found()
+
     def test_a_burn_with_a_silent_beam_sensor_passes(self):
         # A head whose beam sensor gives no output: the tube current and
         # LASER_ON saw the beam, so the burn counts.
@@ -511,6 +523,7 @@ class BurnRunTests(unittest.TestCase):
         with self.assertRaises(Aborted):
             t.fn(Context(run, None, t))
         self.assertEqual(self.daemon.aborted, ["laser.focus"])
+        self.assertIn("emission_seen", run.evidence)    # the test's own reads, on record all the same
         self.assert_found()
         self.assert_restarted_on_found()