ConnectBlueprintPins called SourcePin->MakeLinkTo(TargetPin) but never
notified either node of the new connection, so wildcard-typed pins
(MacroInstance nodes like ForEachLoop, and by extension any wildcard
array/map library call) never resolved their type -- compilation
failed with "type ... is undetermined" regardless of how many times
you recompiled. The real graph editor triggers this via the schema's
TryCreateConnection; MakeLinkTo alone doesn't.
Fix: call NodeConnectionListChanged() on both nodes after linking,
matching what the schema does. Verified against the exact ForEachLoop
scenario that failed twice before the fix -- the Array pin now
resolves to a concrete type and the graph compiles.
Rebuilt via full offline Build.bat (UnrealEditor target) rather than
Live Coding -- Live Coding's patch-link step hit a persistent
"Could not spawn process UbaCli.exe (Error 267)" in this environment,
unrelated to the code change itself (the .cpp compiled cleanly both
times; only the hot-patch link step failed).
