Last piece of the architecture in #2296. The operator: "the prose doesn't have
to live as one offs, there's a central system for managing it."
Two fields, both free-form:
design_systems.guidance the narrative a token table cannot hold — aesthetic,
voice and tone, what is deliberately out of scope.
design_tokens.rationale WHY a token is this value, which is a different
question from `purpose` (what it is FOR). "Success
equals Moss, aligned by design" is a rationale;
"page bg, deepest surface" is a purpose. Rules carry
the first routinely and a token row had nowhere to
put it.
Free-form rather than a column per category, deliberately. A schema with
`voice`, `aesthetic` and `scope` columns would bake one rulebook's table of
contents into every install (rule #115), leaving the next install three empty
columns and nowhere for what it actually cares about. Both nullable: a design
system with no prose at all is complete, not a draft.
`rationale` cascades like `purpose` — deepest non-empty wins — so an app
overriding a colour keeps the family's reasoning rather than blanking it. Same
argument as `supersedes`: the override was about the value, not the meaning.
In the generated sheet the inline comment prefers `purpose` and falls back to
`rationale`, so a token carrying only the why still says something instead of
rendering bare.
