forgetest tests: the confirmed trims of the tool's own unit tests

The cases that tested a mock, a timer, a wording or a table, or that
replayed a judgment a host test already holds, leave forgetest/tests.
What catches a false PASS, keeps the bench safe, or guards the gate
stays.

- test_baseline: the fake sysfs tree is a mixin with no test_ methods,
  so ExtensionFreeTests and BaselineModeTests no longer re-run
  BaselineTests' 25 cases (133 runs, now 45). CoolPublishTests, the
  lamp-fade cases and TransientNotLeftoverTests go; PositionDeadbandTests
  keeps a reading past the band and an unreadable reading, both never
  excused. Both latch-relock cases stay.
- test_fixture: MdnsTests, the three timing cases, the probe's log
  wording, and nine prompt-routing variants go. A live test never runs
  unattended, the arm-press opt-in, the short-press edge, the presence
  press handing over the arm press, and the arm notice dropping at the
  press stay (35 cases, now 21).
- test_cloud_suite: three false-PASS guards stay: the latch open at a
  dark print's button, a lid stop that is not edge-driven, the kernel
  refusing the resume. The guards for the latch unlocking in the hold
  and a paused print resuming left with their catalog tests in 6a434bb.
  The rest go, with the harness pieces and the hunt-lid fixture only
  they read (41 cases, now 3).
- test_cooling_suite: GateOffTests, CriticalTierTests, FanGateTests and
  FansQuietTests go with their harness; the flow verdict's log reads
  stay: only the text after the offset, never an older verdict before it
  (the flow-under-load false-PASS guard), a rotated log read whole.
- test_queue: RunClockTests and three ordering cases go, and refusals
  are judged by a reason given, not its words; both live
  acknowledgment cases stay.
- test_takeover_position: the six cases that judge the head and move
  nothing stay.
- test_camera_home_return: the five cases where the head must not move
  stay, and so do the three that check the hand-back jog's direction and
  distance (homed, unhomed with the counters not counted twice, after
  cloud mode): a wrong sign or a double count drives the head into the
  gantry stops (15 cases, now 8).
- test_server: the keep-alive and ETag cases, the takeover and scope
  half of the bench case, and the page's self-contained asserts
  (test_page.py's) go.
- test_operator: the wording cases, the fixture case (test_fixture.py's)
  and JournalTests go.
- test_mode: the supervisor timeout table goes.
- test_takeover_client: the listener, the offline service back, the
  online client without the hunt, and GRBL under no marker stay.
- test_responsiveness: PageTests and ImplementationCostTests go; the
  log cache keeps appends, a partial line, a replaced file and a fresh
  list, and the fingerprint cache a changed manifest and one with no
  content hash.
- test_bench_registry: GfbenchTests and two description and argument
  pins go.
- test_installer: the log-format and TLS-wording cases and
  InstallerShapeTests go; the die case checks the reason is in the log,
  not its format.
- test_image: KernelIdentTests and the registration pin go.

Each file's __main__ guard now ends the file, and the docstrings say what
each still proves.

Proof: each of the fifteen files passes under Linux as forgetest-ci
discovers it, and pyflakes reports nothing new in them.

Acceptance: none; test-only.

forgetest/tests/test_mode.py

@@ -83,27 +83,6 @@ class SwitchModeTests(unittest.TestCase):
         self.assertTrue(ok, detail)
         self.assertEqual(self.fc.posts, [])
 
-    def test_the_supervisors_levers_get_the_slow_timeout(self):
-        from forgetest import hw
-        fc = hw.Forgectrl(timeout=1.0, slow_timeout=2.0)
-        self.assertEqual(fc.timeout_for("POST", "/mode"), 2.0)
-        self.assertEqual(fc.timeout_for("POST", "/controller/start"), 2.0)
-        self.assertEqual(fc.timeout_for("POST", "/controller/stop"), 2.0)
-        self.assertEqual(fc.timeout_for("GET", "/mode"), 1.0)
-        self.assertEqual(fc.timeout_for("POST", "/settings"), 1.0)
-        self.assertGreater(hw.SLOW_TIMEOUT_S, 15.0)         # forgectrl's first-report wait
-        # a switch that answers after the ordinary timeout still lands
-        import time
-
-        def on_post(path, form):
-            time.sleep(1.5)
-            self.fc.state["mode"] = dict(self.fc.state["mode"], mode="cloud")
-            return None
-        self.fc.on_post = on_post
-        st, body = fc.post("/mode", data={"controller": "cloud"})
-        self.assertEqual(st, 200)                            # 1.5 s > timeout, < slow_timeout
-        self.assertEqual(self.fc.state["mode"]["mode"], "cloud")
-
     def test_cloud_to_grbl_switches_and_waits_for_the_port(self):
         cloud(self.fc)
         b = self.bl()