Bind AI energy level on washer; switch/select split, drop translations

Issue #40: /energy/ailevel/vs/0 was unbound on a plain washer. The
capability already existed for fridges but was gated off entirely on
single-level hardware (the common case), so it's moved to common.py
(cross-family, like fridge + washer now) and split into two entities:
a switch when supportedAiLevel has exactly one entry (aiLevel is really
just an on/off toggle there), and a select otherwise, with '0' (off)
synthesized back into the select's options since supportedAiLevel never
lists it but it's a real observed value.

Also drops the translation_key/strings.json entries -- aiLevel's raw
digit values already render fine untranslated, and translating a
handful of levels can't cover devices with more.

custom_components/localthings/registry/by_type/refrigerator.py

@@ -20,7 +20,7 @@ REGISTRY = DeviceRegistry(
         dishwasher.DIAGNOSIS,
         fridge.ICEMAKER_NIGHTTIME,
         fridge.FLEX_ZONE,
-        fridge.AI_ENERGY_LEVEL,
+        common.AI_ENERGY_LEVEL,
         fridge.REFRIGERATION,
         fridge.AUTOFILL,
         fridge.WELCOME_LIGHTING,

custom_components/localthings/registry/by_type/washer.py

@@ -19,6 +19,7 @@ REGISTRY = DeviceRegistry(
         common.ALARMS,
         common.ENERGY_METER,
         common.WATER_METER,
+        common.AI_ENERGY_LEVEL,
         operational.OPERATIONAL_STATE,
         dishwasher.DIAGNOSIS,
         fridge.FIRMWARE_UPDATE,

custom_components/localthings/registry/capabilities/common.py

@@ -11,7 +11,7 @@ against live device dumps:
   /filter/waterfilter/vs/0  -> x.com.samsung.da.filterUsage / filterStatus
 """
 from ..capability import Capability
-from ..entities import BinarySensorDesc, SensorDesc, SwitchDesc
+from ..entities import BinarySensorDesc, SelectDesc, SensorDesc, SwitchDesc
 
 
 def _num(v):
@@ -231,3 +231,63 @@ WATER_FILTER = Capability(
                    name='Filter status', icon='mdi:filter-check'),
     ),
 )
+
+# AI energy-saving level -- '0' is off, and supportedAiLevel lists the
+# additional level(s) the device offers ('1' meaning just "on" on most
+# hardware, but multi-level boards have been reported). Verified cross-family:
+# fridge (issue #21) and washer (issue #40) both expose this href.
+#
+# supportedAiLevel is a single-entry list on most captured hardware, where a
+# select would offer only one real choice against an implicit "off" -- shown
+# as a switch instead. '0' itself is never in supportedAiLevel but has been
+# observed live as the off value of aiLevel, so the select synthesizes it
+# back in as an explicit option rather than leaving no way to turn off.
+#
+# No translation_key: aiLevel's values are plain digit strings, and
+# select.py's _display() already renders an untranslated numeric string
+# as-is -- there's nothing a strings.json entry adds that's worth maintaining
+# against an unknown, growing number of future levels.
+
+
+def _ai_energy_supported_levels(rep):
+    """supportedAiLevel as a list -- a stray scalar (e.g. a string) must not
+    be len()-checked as if it were a list."""
+    sl = rep.get('supportedAiLevel')
+    return list(sl) if isinstance(sl, (list, tuple)) else []
+
+
+def _ai_energy_level_options(resources):
+    rep = resources.get('/energy/ailevel/vs/0') or {}
+    return ['0', *_ai_energy_supported_levels(rep)]
+
+
+def _ai_energy_level_write(p, rep, href=None):
+    return ['energy', 'ailevel', 'vs', '0'], {'aiLevel': p}
+
+
+def _ai_energy_level_switch_write(p, rep, href=None):
+    levels = _ai_energy_supported_levels(rep)
+    on_level = levels[0] if levels else '1'
+    return ['energy', 'ailevel', 'vs', '0'], {'aiLevel': on_level if p == 'On' else '0'}
+
+
+AI_ENERGY_LEVEL = Capability(
+    href='/energy/ailevel/vs/0',
+    poll_tier='cold',
+    entities=(
+        SwitchDesc(key='ai_energy_level', field='aiLevel',
+                   name='AI energy level', icon='mdi:leaf',
+                   entity_category='config',
+                   value_fn=lambda v: v != '0',
+                   exists_fn=lambda rep, resources: (
+                       len(_ai_energy_supported_levels(rep)) == 1),
+                   write_fn=_ai_energy_level_switch_write),
+        SelectDesc(key='ai_energy_level', field='aiLevel',
+                   name='AI energy level', icon='mdi:leaf',
+                   entity_category='config',
+                   options=_ai_energy_level_options,
+                   exists_fn=lambda rep, resources: (
+                       not rep or len(_ai_energy_supported_levels(rep)) > 1),
+                   write_fn=_ai_energy_level_write),
+    ),
+)

custom_components/localthings/registry/capabilities/fridge.py

@@ -588,33 +588,6 @@ FLEX_ZONE = Capability(
     ),
 )
 
-# ---------------------------------------------------------------------------
-# AI energy-saving level
-#
-# supportedAiLevel is a single-entry list ('1' only) on some hardware, where
-# a select would offer no real choice — gated to >1 supported level.
-# ---------------------------------------------------------------------------
-
-AI_ENERGY_LEVEL = Capability(
-    href='/energy/ailevel/vs/0',
-    poll_tier='cold',
-    entities=(
-        # Only levels '1'/'2' have translated labels in strings.json/translations;
-        # a higher supportedAiLevel entry renders as its raw value until added.
-        SelectDesc(key='ai_energy_level', field='aiLevel',
-                   name='AI energy level', icon='mdi:leaf',
-                   translation_key='ai_energy_level',
-                   entity_category='config',
-                   options_field='supportedAiLevel',
-                   exists_fn=lambda rep, resources: (
-                       not rep or (
-                           isinstance((sl := rep.get('supportedAiLevel')), (list, tuple))
-                           and len(sl) > 1)),
-                   write_fn=lambda p, rep, href=None: (
-                       ['energy', 'ailevel', 'vs', '0'], {'aiLevel': p})),
-    ),
-)
-
 # ---------------------------------------------------------------------------
 # Firmware update
 # ---------------------------------------------------------------------------

custom_components/localthings/strings.json

@@ -148,12 +148,6 @@
           "180": "3 hr",
           "240": "4 hr"
         }
-      },
-      "ai_energy_level": {
-        "state": {
-          "1": "Level 1",
-          "2": "Level 2"
-        }
       }
     },
     "sensor": {

custom_components/localthings/translations/en.json

@@ -148,12 +148,6 @@
           "180": "3 hr",
           "240": "4 hr"
         }
-      },
-      "ai_energy_level": {
-        "state": {
-          "1": "Level 1",
-          "2": "Level 2"
-        }
       }
     },
     "sensor": {