fix(docx): bookmark a block of drawings alone where its first drawing is anchored

CHANGELOG.md

@@ -8,6 +8,27 @@ follow semantic versioning; release dates are ISO 8601.
 
 ### Public API
 
+- **A DOCX export bookmarks a block of drawings alone where its first drawing is anchored, so a
+  page reference or a link to its anchor works.**
+  - A section, a container or a layer stack's column holding nothing but drawings writes no
+    paragraph for a bookmark to go round: its drawings are anchored in the paragraphs beside them,
+    or in one written on their page. Its anchor had no bookmark: a link to it named a bookmark the
+    file did not hold, and a page reference to it was written as the number the layout read, which
+    no edit updates, with a report note. The bookmark now goes at the start of the paragraph its
+    first drawing is anchored in — the drawing on the earliest page, highest on it. Word keeps a
+    drawing on its paragraph's page and moves it with that paragraph, so the reference reads the
+    page the block starts on, and goes on reading it once the text above is edited.
+  - Measured in Word 16, fields updated, and LibreOffice 24.2, on such a block on page 2 and on
+    the same file with a page put in ahead of it: before, both editors read 2 in each and carried
+    no link; now both read 2 and then 3, and the link goes to the block's page. So it is for a
+    section and a container of drawings, one opening its page, one alone on its page, one in a
+    panel, a layer stack's column of drawings, and an anchor named with spaces past the 40
+    characters Word keeps; a block at the foot of page 1 whose drawings run onto page 2 reads 1,
+    and then 2.
+  - A block that draws nothing, one whose first drawing stands on a page nothing is written on,
+    and one composed in a table's cell, whose drawings its table draws, still have no bookmark, and
+    the report names the anchor.
+
 - **A DOCX export bookmarks a layer stack's column, so a page reference or a link to its anchor
   works.**
   - A stack whose layers stand side by side is written as a one-row table, each layer's content in
@@ -23,8 +44,8 @@ follow semantic versioning; release dates are ISO 8601.
     carried no link; now both read 2 and then 3, and the link goes to the column's page. So it is
     for a left and a right column, a container, a later layer of a column, a column opening with a
     table, a stack in a panel, and a table of contents' entry.
-  - A column that writes no paragraph — drawings alone — has no bookmark still, and the report
-    names its anchor, as it does a section's of drawings alone.
+  - A column that writes no paragraph — drawings alone — is bookmarked where its first drawing is
+    anchored, as a section of drawings alone is (above).
 
 - **A DOCX export keeps a page break the layout makes by itself after a card where the page
   makes it.**

docs/architecture/backend-capability-matrix.md

@@ -103,7 +103,7 @@ Payload records live in `core` under
 | Capability | PDF (fixed) | PPTX (fixed) | DOCX (semantic) |
 |---|---|---|---|
 | External hyperlinks (fragment- and run-level) | ✅ `PdfLinkAnnotationWriter` + link rects in `PdfFixedLayoutBackend` | ✅ `PptxNavigationWriter` (transparent hotspots for measured span, line, and fragment rectangles, emitted above all content after the fragment pass) | ⚠️ `DocxSemanticBackend.newRun` — a paragraph's, a run's, a picture-in-a-line's and a page zone picture's link is a `w:hyperlink` with an external relationship, a run's own link winning over its paragraph's. A block written as a picture, a drawing or a rule — an image, a barcode, a shape, an ellipse, a line — and a table carry none, and the report names the link |
-| Internal links (anchor jump, forward references) | ✅ `PdfInternalLinkWriter` (two-pass) | ✅ `PptxNavigationWriter` (deferred slide-jump hyperlinks, resolved after all fragments — including across sections) | ⚠️ `DocxSemanticBackend` — an internal `linkTarget` is a `w:hyperlink` with `w:anchor`, on what an external one is written on, and every anchor the export writes is a bookmark: a paragraph's around its text, a section's, container's, table's, image's or barcode's around everything the block wrote, a stack's layer written as a column around what it writes, a rule's around its paragraph (`bookmarkAround`). A drawing floated over the text — a shape, an ellipse, a line not written as a rule — a page zone's paragraph or picture, and a block that writes no paragraph — a section or a container of drawings alone — hold no bookmark: the report names the anchor, a link to it points at no bookmark, and a page reference to it is written as the number the layout found |
+| Internal links (anchor jump, forward references) | ✅ `PdfInternalLinkWriter` (two-pass) | ✅ `PptxNavigationWriter` (deferred slide-jump hyperlinks, resolved after all fragments — including across sections) | ⚠️ `DocxSemanticBackend` — an internal `linkTarget` is a `w:hyperlink` with `w:anchor`, on what an external one is written on, and every anchor the export writes is a bookmark: a paragraph's around its text, a section's, container's, table's, image's or barcode's around everything the block wrote, a stack's layer written as a column around what it writes, a rule's around its paragraph (`bookmarkAround`); a block that writes no paragraph — a section, a container or a column of drawings alone — at the start of the paragraph its first drawing is anchored in, which Word keeps the drawing on the page of. A drawing floated over the text — a shape, an ellipse, a line not written as a rule — a page zone's paragraph or picture, and a block that draws nothing, whose first drawing stands on a page nothing is written on, or that is composed in a table's cell hold no bookmark: the report names the anchor, a link to it points at no bookmark, and a page reference to it is written as the number the layout found |
 | Page references — a table of contents' numbers, `addPageReference(...)` (`PageReferenceNode`) | ✅ `PageReferenceDefinition` lays out the resolved page as text, drawn by `PdfParagraphFragmentRenderHandler` | ✅ the same laid-out text through `PptxParagraphFragmentRenderHandler` | ✅ `DocxSemanticBackend.writePageReference` — a `PAGEREF` field to the anchor's bookmark, as a hyperlink (`\h`), storing the page the layout resolved; the editor recomputes it (LibreOffice on layout, Word on a field update). A reference to an anchor the export writes no bookmark for is the text the page prints, since Word turns a `PAGEREF` to a missing bookmark into an error, and the report names it, as it does the margins and padding on the sides its alignment sets it from, which are not written. `w:updateFields` is not set |
 | Document outline / bookmarks tree | ✅ `PdfBookmarkOutlineWriter` | ⚠️ `PptxNavigationWriter` (no PPTX outline concept — slide names where 1:1, extra bookmarks dropped with a note) | ❌ |