WordArt text effects and transforms, and shape connectors (#416) (#481)

* WordArt text effects and transforms, and shape connectors (#416)

- Model: WordArt text effects on runs (fill solid/gradient/none, outline,
  shadow, glow, reflection), text warps on shapes (all DrawingML presets
  kept, adjust values capped), connector kinds (straight, elbow, curved)
  with glued ends, arrowheads and drawing ids (ShapeExtra).
- DOCX: w14:textFill/textOutline/shadow/glow/reflection in w:rPr,
  a:prstTxWarp in wps:bodyPr, wps:cNvCnPr a:stCxn/a:endCxn,
  a:headEnd/a:tailEnd; glued-to shapes keep their docPr ids.
- Layout/render/PDF: text with effects drawn from glyph outlines as paint
  layers (gradients, shadow/glow bands, faded reflection); warped text
  boxes bent along arch up/down, circle, wave, slant, inflate/deflate,
  chevron and triangle; connectors and arrowheads drawn as paths.
- Engine: insert.wordArt makes a floating WordArt text box with our own
  styles; format.textEffects, wordArt.style/textFill/textOutline/transform,
  shape.connect; glued connectors re-route after object edits.
- UI: WordArt style gallery (Insert, Home › Text Effects, Shape Format ›
  WordArt Styles), Text Fill/Outline/Effects menus, Transform previews
  drawn from the warp geometry, connectors in Insert › Shapes, drag a
  connector end onto a shape to glue it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Fix tests for ShapeExtra, regenerate parity checklist, fmt (#416)

* Regenerate parity checklist after rebase (#416)

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>

Cargo.lock

@@ -5143,6 +5143,7 @@ version = "0.5.0"
 dependencies = [
  "image",
  "js-sys",
+ "kurbo",
  "log",
  "serde",
  "serde_json",