v0.3.0

Added

• Page decoration. page.background (#RRGGBB) paints the colour
  full-bleed on every page, before any content. page.border draws a frame
  measured from the page edge rather than from the content, so it is the
  same on a page holding one line as on a full one: style (single, double,
  dashed, dotted, none; single by default), width (the whole frame, 0.5 by
  default; a double is two rules of a third each), color (black) and
  inset (points from the edge to the outside of the frame, 24 by default).
  Frames are closed rectangles, so corners meet. Validation refuses a frame
  that leaves no room inside it; repair removes an invalid background or
  frame and says so; the JSON schema and agent guide describe both. The
  frame does not move the text: new lint frame-overlap warns when a margin
  is narrower than inset + width. White text on a dark page background is
  not flagged as hidden. Nothing changes for documents without them; their
  bytes are identical.
• PARITY: last-word (and its JS and Python ports), whose document model
  this shares, has neither key yet. Its validator ignores them, so the same
  document writes a .docx without the decoration, and its JSON schema
  (additionalProperties: false on page) rejects them.

Fixed

• Letter spacing no longer leaks from one text run into every later line.
  The writer reset its record of character spacing (Tc) at each text
  object, but Tc is graphics state and persists across BT/ET, so after
  one run with letterSpacing the rest of the page was drawn tracked while
  layout measured it untracked, and lines overflowed their frame. An explicit
  letterSpacing: 0 did not help, because it matched the stale record and no
  Tc was written. Spacing is now tracked per page. Upgrade normally; nothing
  changes for documents that never set letterSpacing. The writer emits no
  other persistent text-state operator (Tw, Tz, TL, Ts, Tr), so
  none had the same defect.