fix(mo1_bragg): omit ACS scan settings from the device configuration

tests/tests_devices/test_mo1_bragg.py

@@ -136,15 +136,17 @@ def test_set_xtal(mock_bragg):
     assert dev.crystal.xtal_enum.get() == 1
 
 
-def test_read_configuration_uses_acs_cache_and_omits_status_pvs(mock_bragg):
+def test_read_configuration_never_touches_acs_and_omits_status_pvs(mock_bragg):
     """The device server re-reads the full configuration whenever any auto-monitored
-    signal updates; the ticking status PVs must not be part of it, and repeated
-    config reads must not hit the ACS controller again while the cache is fresh."""
+    signal updates; neither the ticking status PVs nor the ACS socket signals may be
+    part of it, so no passive read path ever produces a GETVAR."""
     dev = mock_bragg
     config = dev.read_configuration()
-    assert "bragg_scan_settings_s_scan_energy_lo" in config
-    assert "bragg_scan_settings_s_scan_energy_hi" in config
-    assert "bragg_scan_settings_s_scan_scantime" in config
+    # ACS scan settings are omitted: config reads must not touch the socket at all
+    assert "bragg_scan_settings_s_scan_energy_lo" not in config
+    assert "bragg_scan_settings_s_scan_energy_hi" not in config
+    assert "bragg_scan_settings_s_scan_scantime" not in config
+    assert dev.controller.get_var.call_count == 0
     # live status/progress PVs are omitted from the configuration
     assert "bragg_status_heartbeat" not in config
     assert "bragg_scan_control_scan_msg" not in config
@@ -153,15 +155,13 @@ def test_read_configuration_uses_acs_cache_and_omits_status_pvs(mock_bragg):
     assert "bragg_scan_control_scan_time_left" not in config
     assert "bragg_scan_control_scan_done" not in config
 
-    acs_reads = dev.controller.get_var.call_count
-    dev.read_configuration()
-    assert dev.controller.get_var.call_count == acs_reads  # served from cache
-
-    # a config change drops the cache for exactly that signal
+    # explicit reads still work, are cached, and refresh after a put
+    assert dev.scan_settings.s_scan_energy_lo.get() == 0.0
+    dev.scan_settings.s_scan_energy_lo.get()
+    assert dev.controller.get_var.call_count == 1  # second read served from cache
     dev.scan_settings.s_scan_energy_lo.put(7000.0)
-    dev.read_configuration()
-    assert dev.controller.get_var.call_count == acs_reads + 1
     assert dev.scan_settings.s_scan_energy_lo.get() == 7000.0
+    assert dev.controller.get_var.call_count == 2  # put dropped the cache
 
 
 def test_set_xas_settings(mock_bragg):