H: place text files — Word (.docx), RTF, plain text; autoflow

- designcraft-textimport (L3): DOCX (styles by name with spacing/indents/alignment and font,
  size, bold/italic/underline/strike/caps/position; runs, tabs, breaks, footnotes, tables,
  hyperlink/field results; used styles only), RTF (text, paragraphs, bold/italic/underline/
  strike, size, Unicode/cp1252, skipped destinations), plain text (+ tests)
- engine: file.place routes text files into the insertion point, the selected frame or a new
  frame on the page; imported styles added (existing win); removeStyles; autoflow adds pages
  with threaded frames until the story fits (+ test)
- app/web: Place dialogs accept .docx/.rtf/.txt/.md

Co-Authored-By: Claude Opus 5.5 <[email protected]>

xtask/src/layers.rs

@@ -43,6 +43,7 @@ pub const TABLE: &[(&str, Class)] = &[
     ("pdf", Class::Layer(3)),
     ("idml", Class::Layer(3)),
     ("epub", Class::Layer(3)),
+    ("textimport", Class::Layer(3)),
     ("format", Class::Layer(3)),
     ("tools", Class::Layer(4)),
     ("engine", Class::Layer(5)),