Replaces the value-change (site/instance/attribute) entry with a script picker.
ValueChange/Conditional scripts keep the write-and-poll path with the attribute
derived from the trigger config; every other kind is invoked directly through the
traced RouteToCall path with a parameter form from the script's ParameterDefinitions.
New additive FlowDebugRunScriptCommand; run-value-change stays as the CLI escape hatch.
Claude-Session: https://claude.ai/code/session_01NcMG6xXdsJbmD2wYAgkK29