A behavior object carries a "Run in editor" switch next to Enabled. When it is on, the behavior ticks outside of Play and works on the saved model directly - Unity semantics: what it moves is a real change, autosaved and not undoable. Input stays with the editor, so On key never fires while typing. The editor run never bakes placed containers into the model, since that would silently drop their instanceEdits. syncToModel reports whether it wrote anything, and the dirty flag is only raised on change - otherwise a behavior moving something every frame would trigger ~60 saves a second.
todo-notes
A drop box for ideas that come up while work is already in progress, so they are not lost and not squeezed into the running task. One file per topic, free form, any language.
Anything in here is fair game to pick up at any time. When a note is done, move the file to done/
rather than deleting it – the note says what was wanted, the commit says what was built.