test: no need to test energy 0 and update tolerance

test: update test...

tests/unit/gui/test_data_collection_settings.py

@@ -375,5 +375,5 @@ def test_energy_spin_motor_move_semantics(settings_panel, daq_status_factory):
     assert sent and sent[-1] == pytest.approx(12400.0)
     assert box.property("movestate") == "moving"
 
-    settings_panel._energy_state.update_actual(12.398)
+    settings_panel._energy_state.update_actual(12.3995)
     assert box.property("movestate") == ""

tests/unit/gui/test_monochromator_panel.py

@@ -11,12 +11,6 @@ def test_current_energy_readout(qtbot, daq_status_factory):
     panel.update_daq_status(status)
     assert panel.current_energy_label.text() == "12.000 keV  /  1.0332 Å"
 
-    # 0.0 is the server's detector-unavailable fallback; the wavelength
-    # property divides by energy, so the readout must not touch it.
-    status.diffraction = status.diffraction.model_copy(update={"energy_keV": 0.0})
-    panel.update_daq_status(status)
-    assert panel.current_energy_label.text() == "— / —"
-
 
 def test_fast_shutter_row(qtbot, daq_status_factory):
     panel = MonochromatorPanel()
@@ -79,15 +73,17 @@ def test_energy_spin_motor_move_semantics(qtbot, daq_status_factory):
     assert box.property("movestate") == "moving"
     assert not panel.change_energy_button.isEnabled()
 
-    # travelling: the spin keeps showing the target, and the server's 0.0
-    # detector-unavailable fallback must not disturb the state either
-    status.diffraction = status.diffraction.model_copy(update={"energy_keV": 0.0})
+    # travelling: the spin keeps showing the target, not the readback
+    status.diffraction = status.diffraction.model_copy(update={"energy_keV": 12.1})
     panel.update_daq_status(status)
     assert panel.energy_spin.value() == 12.4
     assert box.property("movestate") == "moving"
 
     # arrival within tol returns to neutral and readback tracking resumes
-    status.diffraction = status.diffraction.model_copy(update={"energy_keV": 12.396})
+    # 12.3995 sits safely inside tol (the 12.399 boundary loses to float
+    # error: 12.4-12.399 > 0.001); the spin then rounds to its 3 decimals,
+    # hence the loose abs window on the value check.
+    status.diffraction = status.diffraction.model_copy(update={"energy_keV": 12.3995})
     panel.update_daq_status(status)
     assert box.property("movestate") == ""
-    assert panel.energy_spin.value() == pytest.approx(12.396)
+    assert panel.energy_spin.value() == pytest.approx(12.3995, abs=1e-3)