IO Directory Reference

Directory dependency graph for IO:

Files
	ExternalFilePath.h
	Single, shared implementation of how an element's external-file reference (an appearance image, a custom audio file, a file-based IC sub-circuit) gets resolved on load and represented on save. Every class that owns such a reference routes through these functions instead of reimplementing the same path arithmetic – three independent copies of it had already silently drifted apart before this was extracted (see the "avoid this bug class" thread this was written for).
	FileUtils.h
	RecentFiles.cpp
	RecentFiles.h
	Recent-files list management with filesystem watching.
	Serialization.cpp
	Serialization.h
	Circuit and waveform file serialization/deserialization utilities.
	SerializationContext.h
	Deserialization/serialization context structs passed through load()/save() call chains.
	VersionInfo.h
	Named version predicates for file-format compatibility checks.