fix #10944: Null sentinel initialized=false

DataRuntimeLang::Null sentinel was ctor'd w/ initialized=true
(DataRuntimeLanguage.hh:805 static init, :868 clear_state).
Semantically wrong - Null means "no value set" - and it poisoned
every actuator Erl var via Value=Null at EMSManager.cc:743,
defeating checkForUnusedActuatorsAtEnd's !Value.initialized guard.

Flip the last ctor arg to false at both sites. Audit confirms
dataRuntimeLang->Null has a single caller - zero blast radius.

Update EMSManager_TrendValue_to_Actuator: two pre-SET
EXPECT_TRUE->EXPECT_FALSE to match corrected invariant.

Author: brianlball

src/EnergyPlus/DataRuntimeLanguage.hh

@@ -802,7 +802,7 @@ struct RuntimeLanguageData : BaseGlobalStruct
     Array1D<DataRuntimeLanguage::InternalVarsUsedType> EMSInternalVarsUsed;           // internal data that are used
     Array1D<DataRuntimeLanguage::EMSProgramCallManagementType> EMSProgramCallManager; // program calling managers
     DataRuntimeLanguage::ErlValueType Null = DataRuntimeLanguage::ErlValueType(
-        DataRuntimeLanguage::Value::Null, 0.0, "", 0, 0, false, 0, "", true); // special "null" Erl variable value instance
+        DataRuntimeLanguage::Value::Null, 0.0, "", 0, 0, false, 0, "", false); // special "null" Erl variable value instance; issue #10944
     DataRuntimeLanguage::ErlValueType False = DataRuntimeLanguage::ErlValueType(
         DataRuntimeLanguage::Value::Null, 0.0, "", 0, 0, false, 0, "", true); // special "false" Erl variable value instance
     DataRuntimeLanguage::ErlValueType True = DataRuntimeLanguage::ErlValueType(
@@ -865,7 +865,7 @@ struct RuntimeLanguageData : BaseGlobalStruct
         this->EMSInternalVarsAvailable.deallocate();
         this->EMSInternalVarsUsed.deallocate();
         this->EMSProgramCallManager.deallocate();
-        this->Null = DataRuntimeLanguage::ErlValueType(DataRuntimeLanguage::Value::Null, 0.0, "", 0, 0, false, 0, "", true);
+        this->Null = DataRuntimeLanguage::ErlValueType(DataRuntimeLanguage::Value::Null, 0.0, "", 0, 0, false, 0, "", false); // issue #10944
         this->False = DataRuntimeLanguage::ErlValueType(DataRuntimeLanguage::Value::Null, 0.0, "", 0, 0, false, 0, "", true);
         this->True = DataRuntimeLanguage::ErlValueType(DataRuntimeLanguage::Value::Null, 0.0, "", 0, 0, false, 0, "", true);
 

tst/EnergyPlus/unit/EMSManager.unit.cc

@@ -2592,7 +2592,7 @@ TEST_F(EnergyPlusFixture, EMSManager_TrendValue_to_Actuator)
     EXPECT_FALSE(actuatorDirectErlVar.Value.TrendVariable);
     EXPECT_EQ(0, actuatorDirectErlVar.Value.TrendVarPointer);
     EXPECT_TRUE(actuatorDirectErlVar.Value.Error.empty());
-    EXPECT_TRUE(actuatorDirectErlVar.Value.initialized);
+    EXPECT_FALSE(actuatorDirectErlVar.Value.initialized); // issue #10944: unset until Erl SET runs
 
     auto &actuatorIndirectErlVar = state->dataRuntimeLang->ErlVariable(2);
     EXPECT_EQ("ACTUATOR_SCH_INDIRECT", actuatorIndirectErlVar.Name);
@@ -2605,7 +2605,7 @@ TEST_F(EnergyPlusFixture, EMSManager_TrendValue_to_Actuator)
     EXPECT_FALSE(actuatorIndirectErlVar.Value.TrendVariable);
     EXPECT_EQ(0, actuatorIndirectErlVar.Value.TrendVarPointer);
     EXPECT_TRUE(actuatorIndirectErlVar.Value.Error.empty());
-    EXPECT_TRUE(actuatorIndirectErlVar.Value.initialized);
+    EXPECT_FALSE(actuatorIndirectErlVar.Value.initialized); // issue #10944: unset until Erl SET runs
 
     // Then we have the built in ones
     for (int i = 1; i <= numBuiltInErlVars; ++i) {