Fix #8904: OA node wetbulb actuator silently fails via Python plugin API

[brianlball]

Summary

Fixes #8904 — EMS "Outdoor Air System Node" / "Wetbulb Temperature" actuator has no effect when set via the Python plugin API (getActuatorHandle). Drybulb works; wetbulb is silently discarded.

Scope: Python plugin API path only. Traditional EMS wetbulb overrides work correctly (fixed in PR #6841, which sets IsLocalNode=true during SetupNodeSetPointsAsActuators at EMSManager.cc:1427). The issue's follow-up EMS example appears broken due to a typo (SET cond_dbt = 23.9 should be SET cond_wbt = 23.9) — Node 1's reported Twb=19.41 confirms the traditional path works.

Root cause

SetOANodeValues (OutAirNodeManager.cc:595) gates the PsyWFnTdbTwbPb HumRat recalculation behind if (Node.IsLocalNode). Traditional EMS sets IsLocalNode = true during setup via SetupNodeSetPointsAsActuators (EMSManager.cc:1427), but getActuatorHandle() (datatransfer.cc:457) never does — by the time a Python plugin requests the handle, setup has already run and found no match.

Fix

Two complementary changes:

File	Change
OutAirNodeManager.cc:595	Widen gate: IsLocalNode || EMSOverrideOutAirDryBulb || EMSOverrideOutAirWetBulb — EMS override bools are ground truth set by both traditional and plugin paths
datatransfer.cc:461-468	Set IsLocalNode = true in getActuatorHandle when type is "OUTDOOR AIR SYSTEM NODE", mirroring EMSManager.cc:1427 — covers AirflowNetwork and any other IsLocalNode consumer
OutAirNodeManager.unit.cc	New test

Flow tree

Pre-fix (Python plugin wetbulb override):
├─ Plugin calls getActuatorHandle("Outdoor Air System Node", "Wetbulb Temperature", node)
│  └─ datatransfer.cc:457 — returns handle, but IsLocalNode stays false
├─ Plugin sets actuator value → EMSOverrideOutAirWetBulb = true
└─ SetOANodeValues (OutAirNodeManager.cc:595)
   └─ if (Node.IsLocalNode) → FALSE → skip HumRat recalc → override discarded

Post-fix:
├─ getActuatorHandle — sets IsLocalNode = true (datatransfer.cc:464)
└─ SetOANodeValues (OutAirNodeManager.cc:595)
   └─ if (IsLocalNode || EMSOverrideOutAirDryBulb || EMSOverrideOutAirWetBulb) → TRUE
      └─ PsyWFnTdbTwbPb recalculates HumRat from overridden Twb ✓

Test added

OutAirNodeManager_EMSWetbulbOverride_NoIsLocalNode — two OA nodes with IsLocalNode=false and EMS wetbulb overrides active. Verifies HumRat is recalculated from overridden temps, not left at environment value.

Test plan

• New unit test passes
• Full test suite: 3014/3014 passed
• pre-commit clean
• gcc warning check clean
• CI green