slang-server refuses getScope locations only if edits were sent before didSave

With slang-server 0.3.1, getScope items lose their source locations (empty instLoc uri) after an unsaved didChange, until a didSave. But in a save-then-type race the result depends on order: if the edit went out as didChange before didSave (the normal editor flow) and more typing follows within ~100 ms, later reads stay location-less. If you only send didSave(text) and then type, reads stay normal. Tests that reproduce the 'dirty right after save' case must send the didChange first. Also, didClose without a save does not clear the state; sending didSave with the on-disk text before didClose does.