v0.2.8

• Add: per-feature label box controls on text features — textBoxSize
  (small/medium/large, default medium) for padding and textBoxRadius
  (none(default)/small/medium/round) for corners, on top of textBackground /
  textBorder. The box is drawn only when a fill and/or border is set, and rotates
  with the text. New exported types TextBoxSize / TextBoxRadius.
• Fix/Add (MapLibre): the label box is now a per-feature 9-slice image built on
  demand (styleimagemissing) from the feature's textBackground/textBorder/
  textBoxSize/textBoxRadius — so MapLibre finally honours per-feature box colours,
  padding and corner radius (it previously drew one fixed white/black box).
• Limitation: OpenLayers honours textBoxSize and the colours but not
  textBoxRadius — its native text background is a rectangle (no corner radius).