docs: Chapter numbering in the progress docs

Rebased on the progress-docs restructure: the ROADMAP bullet moved to the
inventory in docs/target-app-parity.md (Books), with a progress-log line.

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

ROADMAP.md

@@ -153,6 +153,8 @@ Newest first.
 - **2026-10-12** · The Effects panel shows the level its settings apply to ("Group: Color Dodge 100%") and, as in InDesign, Isolate Blending and Knockout Group for a selected group. No readiness percentage change.
 - **2026-10-11** · Properties gains InDesign's Pathfinder section (Add, Subtract, Intersect, Exclude Overlap, Minus Back) with several objects selected; section titles and icon buttons have accessible names. No readiness percentage change.
 - **2026-10-12** · The Eyedropper samples a placed image: clicking the photo with text (or objects) selected fills them with the image's colour under the pointer, as an unnamed colour (`color.sample`), as in InDesign. Images on locked layers can be sampled. No readiness percentage change.
+- **2026-10-11** · Document chapter numbering (#341): style, automatic, start at, same as previous
+  document in the book; Update Numbering resolves it in book order.
 - **2026-10-12** · Words in capitals hyphenate like capitalized words (FERRUM COM-MODI), as in InDesign; Hyphenate Capitalized Words off keeps them whole. No readiness percentage change.
 - **2026-10-11** · `transform.move {copy}`, Edit › Duplicate and Step and Repeat return the copies' ids, so a script can go on with them. No readiness percentage change.
 - **2026-10-11** · `object.fill` and `object.stroke` refuse a swatch name the document doesn't have (it painted nothing) and suggest the name meant (`Paper` → `[Paper]`). No readiness percentage change.

docs/target-app-parity.md

@@ -350,7 +350,7 @@ It is evidence of breadth: each item exists. It is not a claim of InDesign-level
 - View ▸ Separations Preview (`view.separations`): one process plate as ink density, or areas over an ink limit in red (a GCR preview of the rendered view; spot plates and the flattener preview aren't there).
 - Separations Preview plates now come from each object's own colour (CMYK as authored; RGB and images through the colour settings, images via a cached 17³ table), so pure black shows only on the black plate.
 - Language (Character panel ▸ Language, Properties ▸ Character, `type.char {language}`): text in other languages isn't hyphenated or spell-checked with the English dictionaries, typographer's quotes follow the language (German „…“, French and Russian «…», Swiss, Spanish, Dutch, Nordic, Japanese and Traditional Chinese 「…」, Simplified Chinese “…”), the font's localized forms (OpenType `locl`: Turkish i, Bulgarian Cyrillic, Japanese / Chinese / Korean glyph variants) follow it too, and so does the fallback for CJK characters the font lacks (with Draw Missing Glyphs from Fallback Fonts on): Japanese, Simplified Chinese, Traditional Chinese and Korean each try their own installed system fonts (Japanese starts with the craft-fonts Japanese faces, Mincho first, when built with them; Hangul, kana and Bopomofo pick their language's fonts whatever the language). Language names from IDML keep their spelling; locale codes as InDesign writes them for some languages (`de_DE_2006`, `nl_NL_2005`; any `ll`, `ll_CC`, `ll-CC`) are their language and region for all of the above, and Chinese is also recognised in its common spellings ("Simplified Chinese", "Chinese (Traditional)", `zh_CN`, `zh-Hant`). Spanish is hyphenated with Javier Bezos's Liang patterns (`hyph-es.tex` 5.0, MIT) and Portuguese with hyph-utf8's `hyph-pt.tex` 1.4 (BSD-3-Clause), both through the `hypher` crate; hyphenation for other languages isn't bundled yet.
-- Books (`book.new/open/add/remove/list/styleSource/paginate/syncStyles/exportPdf`, Book panel): `.dcbook` files, continuous page numbering, style sync from a style source, one merged PDF.
+- Books (`book.new/open/add/remove/list/styleSource/paginate/syncStyles/exportPdf`, Book panel): `.dcbook` files, continuous page numbering, chapter numbers resolved in book order (Automatic, Start Chapter Numbering at, Same as Previous Document; `layout.chapterNumbering`, with a style for Chapter Number variables and cross-references), style sync from a style source, one merged PDF. Section prefixes follow InDesign's rule (up to 8 characters, no + or comma).
 - Book numbering/style updates validate and serialize all targets before changing the first chapter. They write only closed native chapters, checking canonical paths for open aliases; IDML remains a read-only style source and PDF input. Snapshots are staged on disk with at most 4,096 chapter records in memory. Each replacement is atomic; a later write failure explicitly lists completed chapters rather than claiming whole-book rollback. Import/serialization memory limits and advanced book TOC/index work remain separate.
 - Track Changes (`changes.track/list/acceptAll/rejectAll`, Type ▸ Track Changes): typing is marked added (highlighted on screen), deletions are kept but hidden from layout and exports until accepted or rejected. Per-change accept/reject and authors aren't there yet.
 - Track Changes: per-change Accept / Reject (`changes.accept`, `changes.reject`) and a Track Changes panel listing every change.