Fix AI energy level platform-flip bug found in Opus review

The switch and select shared a stub-time asymmetry: only the select had a
`not rep` carve-out, so an unfetched-stub rep at the moment platforms are
set up (entity creation runs once, ever) would instantiate a Select, while
flatten() re-evaluates exists_fn every poll against live data -- once the
resource populated to a single-level list, the switch's exists_fn would win
instead and feed the already-created Select a bool through their shared
'ai_energy_level' key, which isn't a valid select option.

Dropped the stub carve-out from the select's exists_fn so both sides
require real, populated data to decide the platform -- on a device that
stubs this cold-tier href on its very first poll, the entity now simply
doesn't appear until a reload, instead of appearing as the wrong widget
type. Added tests for the missing/empty-list supportedAiLevel shapes on
both widgets and a regression test locking in the stub behavior.

custom_components/localthings/registry/capabilities/common.py

@@ -277,6 +277,22 @@ AI_ENERGY_LEVEL = Capability(
     href='/energy/ailevel/vs/0',
     poll_tier='cold',
     entities=(
+        # No `not rep` stub carve-out on either side, unlike most exists_fn
+        # gates in this file -- entity creation only ever runs once, against
+        # whichever snapshot happens to be current the moment platforms are
+        # set up (see entity._is_included / __init__.py's
+        # async_config_entry_first_refresh-before-forward-entry-setups
+        # ordering), while flatten() re-evaluates exists_fn every poll
+        # against live data. Both descriptors share key='ai_energy_level',
+        # so if a stub carve-out let one of them win at setup time while the
+        # other wins once real data lands, flatten() would feed the
+        # instantiated entity a value shaped for the other platform (e.g. a
+        # bool into a Select). Requiring real, populated data on both sides
+        # keeps the entity-creation decision and the live-value decision in
+        # permanent agreement -- the cost is this entity doesn't appear
+        # until a reload if the device's very first poll stubs this
+        # cold-tier href, the same reload already required to fix which
+        # platform got picked in that case.
         SwitchDesc(key='ai_energy_level', field='aiLevel',
                    name='AI energy level', icon='mdi:leaf',
                    entity_category='config',
@@ -289,7 +305,7 @@ AI_ENERGY_LEVEL = Capability(
                    entity_category='config',
                    options=_ai_energy_level_options,
                    exists_fn=lambda rep, resources: (
-                       not rep or len(_ai_energy_supported_levels(rep)) > 1),
+                       len(_ai_energy_supported_levels(rep)) > 1),
                    write_fn=_ai_energy_level_write),
     ),
 )

tests/test_common_capabilities.py

@@ -166,10 +166,15 @@ class TestAiEnergyLevelSwitch:
         desc = self._desc()
         assert desc.exists_fn({'aiLevel': '1', 'supportedAiLevel': '1'}, {}) is False
 
+    def test_hidden_when_supported_level_missing(self):
+        desc = self._desc()
+        assert desc.exists_fn({'aiLevel': '1'}, {}) is False
+
+    def test_hidden_when_supported_level_empty_list(self):
+        desc = self._desc()
+        assert desc.exists_fn({'aiLevel': '0', 'supportedAiLevel': []}, {}) is False
+
     def test_hidden_on_empty_stub_rep(self):
-        """Unlike the select, the switch requires a confirmed single-entry
-        list -- an unfetched stub defaults to the select branch instead (see
-        TestAiEnergyLevelSelect.test_shown_for_empty_stub_rep)."""
         desc = self._desc()
         assert desc.exists_fn({}, {}) is False
 
@@ -201,11 +206,17 @@ class TestAiEnergyLevelSelect:
         assert desc.exists_fn({'aiLevel': '1', 'supportedAiLevel': ['1', '2']}, {}) is True
         assert desc.exists_fn({'aiLevel': '1', 'supportedAiLevel': ['1']}, {}) is False
 
-    def test_shown_for_empty_stub_rep(self):
-        """An empty {} rep is /device/0's not-yet-fetched-stub carve-out --
-        defaults to the select so sub-polls can populate it either way."""
+    def test_hidden_when_supported_level_is_non_list_scalar(self):
         desc = self._desc()
-        assert desc.exists_fn({}, {}) is True
+        assert desc.exists_fn({'aiLevel': '1', 'supportedAiLevel': '12'}, {}) is False
+
+    def test_hidden_when_supported_level_missing(self):
+        desc = self._desc()
+        assert desc.exists_fn({'aiLevel': '1'}, {}) is False
+
+    def test_hidden_when_supported_level_empty_list(self):
+        desc = self._desc()
+        assert desc.exists_fn({'aiLevel': '0', 'supportedAiLevel': []}, {}) is False
 
     def test_no_translation_key(self):
         """aiLevel's values are plain digits that render fine untranslated
@@ -232,6 +243,28 @@ class TestAiEnergyLevelSelect:
         assert body == {'aiLevel': '2'}
 
 
+class TestAiEnergyLevelStubDoesNotDecideThePlatform:
+    """Issue found in review: entity *creation* runs once, against whatever
+    snapshot is current when platforms are set up (see
+    __init__.py's async_config_entry_first_refresh-before-forward-entry-setups
+    ordering), while flatten() re-evaluates exists_fn every poll against live
+    data. Both descriptors share key='ai_energy_level' (see adapter._key), so
+    if a stub carve-out let one of them win at setup time while the other
+    wins once real data lands, flatten() would feed the already-instantiated
+    entity a value shaped for the other platform (e.g. a bool into a Select
+    expecting a string option). Neither side gets a `not rep` carve-out, so
+    an unfetched stub can never win entity creation for either platform --
+    the entity simply doesn't appear until a reload happens with real data,
+    same as any other exists_fn-gated entity in this codebase that's unlucky
+    on first-poll timing, instead of appearing as the wrong widget type."""
+
+    def test_neither_widget_exists_on_empty_stub_rep(self):
+        switch = _ai_energy_level_desc('SwitchDesc')
+        select = _ai_energy_level_desc('SelectDesc')
+        assert switch.exists_fn({}, {}) is False
+        assert select.exists_fn({}, {}) is False
+
+
 class TestSelfCheckError:
     """Self-check diagnostic error list -- surfaced on hardware that reports
     x.com.samsung.da.error, joined into a single display string."""