fix(operational): support delayEndTime as an alternate delay-start field

tests/test_operational_capability.py

@@ -6,3 +6,35 @@ def test_machine_state_maps_samsung_to_ocf():
     assert ms.value_fn('Run') == 'active'
     assert ms.value_fn('Pause') == 'pause'
     assert ms.value_fn('Ready') == 'idle'
+
+
+class TestDelayFieldFallback:
+    def test_reads_delay_end_time_when_delay_start_time_absent(self):
+        from custom_components.localthings.registry.capabilities.operational import OPERATIONAL_STATE
+        desc = next(e for e in OPERATIONAL_STATE.entities if e.key == 'delay_start_hours')
+        rep = {'x.com.samsung.da.delayEndTime': '02:30:00'}
+        assert desc.rep_fn(rep) == 2.5
+
+    def test_prefers_delay_start_time_when_both_present(self):
+        from custom_components.localthings.registry.capabilities.operational import OPERATIONAL_STATE
+        desc = next(e for e in OPERATIONAL_STATE.entities if e.key == 'delay_start_hours')
+        rep = {
+            'x.com.samsung.da.delayStartTime': '01:00:00',
+            'x.com.samsung.da.delayEndTime': '02:00:00',
+        }
+        assert desc.rep_fn(rep) == 1.0
+
+    def test_write_targets_delay_end_time_when_that_is_what_device_reports(self):
+        from custom_components.localthings.registry.capabilities.operational import OPERATIONAL_STATE
+        desc = next(e for e in OPERATIONAL_STATE.entities if e.key == 'delay_start_hours')
+        rep = {'x.com.samsung.da.delayEndTime': '00:00:00'}
+        path, body = desc.write_fn(1.5, rep)
+        assert path == ['operational', 'state', 'vs', '0']
+        assert body == {'x.com.samsung.da.delayEndTime': '1:30:00'}
+
+    def test_write_targets_delay_start_time_by_default(self):
+        from custom_components.localthings.registry.capabilities.operational import OPERATIONAL_STATE
+        desc = next(e for e in OPERATIONAL_STATE.entities if e.key == 'delay_start_hours')
+        rep = {'x.com.samsung.da.delayStartTime': '00:00:00'}
+        path, body = desc.write_fn(1.5, rep)
+        assert body == {'x.com.samsung.da.delayStartTime': '1:30:00'}