RESEARCH QUESTION — THREE AGES OF THE SAME PAGE
Switch between them: the layout never changes, only how much of it is filled. A freshly promoted page is mostly provenance and that is its finished state, not a stub. The evidence spread is two structurally separate columns with a balance strip above them, so a one-sided literature is visible before you have to think about it.
ATTACHING A SOURCE — AND DECIDING WHICH SIDE IT IS ON
⌘⇧A from anywhere on the page, or drag a source in from the Reader. Side is a choice with three answers, not two: unsorted exists so that attaching never costs a judgement you have not made yet. The note and the annotation links are the part worth typing, and both are optional.
EDITING THE ANSWER — AND THE OPTIONAL “WHY”
Left: editing is a plain text field and ⌘⏎ commits. The revision is recorded either way. Right: ⌥⏎ instead opens one line for what changed your mind, with the source, annotation or experiment responsible attachable in the same gesture. Nothing blocks the save; the note can also be added to any past revision later, from the history.
POSITION HISTORY — A TRAIN OF THOUGHT, NOT A DIFF LOG
Seven revisions over eleven months; three of them carry a why. Explained revisions are the narrative and get the full width. The unexplained ones are not hidden — they collapse into a dated rule that still shows the position moved, and any of them can be annotated later from here.