ProcessNode is now in LumaCore, exposing AsyncStream for
events, REPL results, ITrace captures, module snapshots,
and session detach notifications. No delegates, no
@Published — consumers subscribe with for-await.
Luma retains ProcessNodeViewModel as a thin ObservableObject
wrapper that subscribes to the streams and handles SwiftData
persistence (inserting REPLCells, ITraceCaptures) and R2
integration.
RuntimeEvent is now a self-contained LumaCore value type
with source and payload enums instead of object references.
The Luma-side DisplayEvent bridges to views by carrying a
ProcessNodeViewModel reference alongside the core event.
WIP: views not yet updated for the rename — the Xcode build
needs mechanical updates across ~14 files to use
ProcessNodeViewModel and DisplayEvent.
