fix: restore empty-stub carve-out on the new energy sensors; dedupe flex-zone set build

Review follow-up (Opus + /simplify) on the previous commit:

- power_energy_kwh/energy_saved_kwh/energy_last_month_kwh/
  energy_this_month_kwh used a plain `field in rep` exists_fn, unlike their
  siblings power_watts/energy_kwh in the same capability. Per
  entity._is_included, an explicit exists_fn bypasses the stub carve-out
  entirely -- an empty {} rep at platform setup (device/0 returned a
  not-yet-fetched stub) would permanently drop these entities for the
  session instead of picking them up once a sub-poll populates the
  resource. Restore the same `not rep or ...` guard used above.
- fridge._flex_zone_current/_flex_zone_write independently rebuilt the same
  supportedOptions set; factor into _flex_zone_supported.
- note in a comment that the flex-zone match assumes at most one
  modes/supportedOptions overlap (true on every dump seen); add the
  missing negative assertion that dry_level self-gates off on a plain
  washer (was only positively asserted on the combo fixture).

custom_components/localthings/registry/capabilities/common.py

@@ -177,29 +177,36 @@ ENERGY_METER = Capability(
                        not rep or 'x.com.samsung.da.cumulativePower' in rep)),
         # cumulativeConsumption is a second, independently-varying running
         # total alongside cumulativePower -- some fridges (issue #26) report
-        # both. Self-gates off where only cumulativePower is present.
+        # both. Self-gates off where only cumulativePower is present. `not
+        # rep or` keeps the same empty-{} stub carve-out as power_watts/
+        # energy_kwh above -- without it, an exists_fn permanently drops the
+        # entity if setup happens to land on a not-yet-fetched stub.
         SensorDesc(key='power_energy_kwh', field='x.com.samsung.da.cumulativeConsumption',
                    name='Power energy', device_class='energy',
                    state_class='total_increasing', unit='kWh', value_fn=wh_to_kwh,
-                   exists_fn=lambda rep, resources: 'x.com.samsung.da.cumulativeConsumption' in rep),
+                   exists_fn=lambda rep, resources: (
+                       not rep or 'x.com.samsung.da.cumulativeConsumption' in rep)),
         # AI Energy Mode's lifetime savings estimate vs. an unoptimized
         # baseline -- present on some models (e.g. TP1X_REF_21K, issue #21/
         # #27) and absent on others (issue #20/#26), unlike cumulativePower.
         SensorDesc(key='energy_saved_kwh', field='x.com.samsung.da.cumulativeSavedPower',
                    name='Energy saved', device_class='energy',
                    state_class='total_increasing', unit='kWh', value_fn=wh_to_kwh,
-                   exists_fn=lambda rep, resources: 'x.com.samsung.da.cumulativeSavedPower' in rep),
+                   exists_fn=lambda rep, resources: (
+                       not rep or 'x.com.samsung.da.cumulativeSavedPower' in rep)),
         # Monthly billing-cycle totals -- the completed prior month and the
         # in-progress current month. Not ever-increasing (each resets at
         # month boundary), so no state_class.
         SensorDesc(key='energy_last_month_kwh', field='x.com.samsung.da.monthlyConsumption',
                    name='Energy (last month)', device_class='energy',
                    unit='kWh', value_fn=wh_to_kwh,
-                   exists_fn=lambda rep, resources: 'x.com.samsung.da.monthlyConsumption' in rep),
+                   exists_fn=lambda rep, resources: (
+                       not rep or 'x.com.samsung.da.monthlyConsumption' in rep)),
         SensorDesc(key='energy_this_month_kwh', field='x.com.samsung.da.thismonthlyConsumption',
                    name='Energy (this month)', device_class='energy',
                    unit='kWh', value_fn=wh_to_kwh,
-                   exists_fn=lambda rep, resources: 'x.com.samsung.da.thismonthlyConsumption' in rep),
+                   exists_fn=lambda rep, resources: (
+                       not rep or 'x.com.samsung.da.thismonthlyConsumption' in rep)),
     ),
 )
 

custom_components/localthings/registry/capabilities/fridge.py

@@ -543,14 +543,22 @@ PANTRY_ZONE = Capability(
 # Write replaces only that item; other flags are preserved.
 # ---------------------------------------------------------------------------
 
+def _flex_zone_supported(rep):
+    return set(rep.get('x.com.samsung.da.supportedOptions') or ())
+
+
 def _flex_zone_current(rep):
+    # Every dump seen has at most one modes/supportedOptions overlap, so
+    # "first match" and "strip all matches" (in the write below) agree. If a
+    # future device ever reports two, this reads the first and the write
+    # would drop both -- revisit if that turns up.
     modes = rep.get('x.com.samsung.da.modes') or []
-    supported = set(rep.get('x.com.samsung.da.supportedOptions') or ())
+    supported = _flex_zone_supported(rep)
     return next((m for m in modes if m in supported), None)
 
 
 def _flex_zone_write(p, rep, href=None):
-    supported = set(rep.get('x.com.samsung.da.supportedOptions') or ())
+    supported = _flex_zone_supported(rep)
     modes = [m for m in (rep.get('x.com.samsung.da.modes') or []) if m not in supported]
     modes.append(p)
     return ['mode', 'vs', '0'], {'x.com.samsung.da.modes': modes}

tests/test_washer_capabilities.py

@@ -271,7 +271,8 @@ class TestFlexWashAndComboFixturesHaveCompleteCoverage:
             log=unbound.append,
         )
         assert unbound == []
-        flatten(bound, resources)  # doesn't raise
+        state = flatten(bound, resources)
+        assert 'dry_level' not in state  # plain washer -- no supportedDryLevel field
 
     def test_dryer_combo(self):
         from custom_components.localthings.registry.adapter import flatten