- Generalize the recipe into a .btn-{tone} family: add .btn-danger / .btn-warn
siblings sharing one hover-dim, and migrate the two hand-rolled tone-action
buttons (ConfirmProvider danger confirm, Banner warning action) onto them, so
primary/danger/warn action paints can't drift.
- Reword the recipe comment: it owns paint + one standard hover-dim (not
'PAINT-ONLY' — that mislabel obscured the hover behaviour).
- Drop the now-redundant hover:opacity-90 from Banner's action-button base (each
tone's recipe supplies the hover).
The 3 previously hover-less primary buttons keep the standard hover-dim gained in
the prior commit (intentional consistency; now accurately documented). Gate green
(tsc/eslint-0/prettier/knip/vitest 79); self-E2E confirmed btn-danger/btn-warn
compute to their tone/tone-fg tokens.