Add to an existing note instead of starting a new one

When you are saving a note and the project already has notes in it, the panel offers an Add to field. Pick an existing note and what you highlighted is appended to it instead of creating another one.

The title and source fields disappear when you do this, because the note already has both.

This is deliberately notes only. A research note genuinely grows; a script does not. Merging scripts would put many separately approvable pieces behind one status and one node on the map.