"""central prose on a design system, and rationale on a token

Revision ID: 0074
Revises: 0073
Create Date: 2026-07-31

The operator's shape for #254: prose doesn't live as one-offs, it lives centrally
on the system. Two fields rather than one per category:

  design_systems.guidance   the narrative a token table cannot hold — aesthetic,
                            voice and tone, what is deliberately out of scope.
                            Markdown, free-form.
  design_tokens.rationale   WHY this 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.

Free-form rather than a column per category on purpose. A schema with `voice`,
`aesthetic` and `scope` columns would bake one rulebook's table of contents into
every install (rule #115), and the next install's design system would have three
empty columns and nowhere to put what it actually cares about.

Both nullable: a design system with no prose at all is complete, not a draft.

Downgrade drops both columns and the prose with them.
"""
from alembic import op
import sqlalchemy as sa


revision = "0074"
down_revision = "0073"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.add_column("design_systems", sa.Column("guidance", sa.Text(), nullable=True))
    op.add_column("design_tokens", sa.Column("rationale", sa.Text(), nullable=True))


def downgrade() -> None:
    op.drop_column("design_tokens", "rationale")
    op.drop_column("design_systems", "guidance")
