fix(docx): hold a ruled table's first and last rows less the rule and a half they carry

CHANGELOG.md

@@ -8,6 +8,15 @@ follow semantic versioning; release dates are ISO 8601.
 
 ### Public API
 
+- **A ruled table's first and last rows keep the page's height in DOCX.** A row the page holds
+  at a height is written that height less what its cells take around their content, since
+  Word, as LibreOffice, reads a row's written height as its content. Word gives a rule between
+  two rows half to each row, and the rule above the table and the one below it whole, so the
+  first row and the last carry a rule and a half; written less one rule, each stood half a rule
+  taller. `EditorialProposal`'s timeline and investment tables each stood that much taller, and
+  its second page ran 2.5pt low by its acceptance block, 1.2pt of it these tables. Lines more
+  than 2pt off fall from 11 to none for `EditorialProposal` in Word, and from 22 to 11 across
+  the corpus; the corpus's mean |drift| in Word falls from 0.43 to 0.34pt.
 - **A row's cell whose last line hangs below the row takes it out of the gap under the row in
   DOCX.** A line held to an icon reaches as far below the page's line as the icon's ink, and
   gives that room back out of the space above what follows. The last line of a cell had

docs/recipes/docx-export.md

@@ -69,7 +69,7 @@ creation date is real metadata.
 |---|---|
 | Paragraphs | Word paragraphs with alignment, font, size, colour, bold/italic/underline; inline runs preserved; a `\n` in the text is a line break (`w:br`), which Word would otherwise read as a space; a table cell's `text("a\nb")` stays one line, as the page sets it; a `bulletOffset` of spaces is an indent — the wrapped lines (`FROM_SECOND_LINE`), the first (`FIRST_LINE`) or all of them start that far in, measured in the paragraph's style as the page measures it; a prefix with letters in it is not written, but the wrapped lines still start after the spaces the page covers it with; no prefix is applied to a paragraph written over the flow, as one of an overlay's left-and-right pair, or in a header or footer. A body paragraph the layout moves to a new page keeps the space the layout leaves above its text there — its own top edge, the edges of the containers opening with it, and the gap before it where the gap did not fit at the foot of the page above — as an empty line that tall before it, kept with it, since Word drops a paragraph's space above at the top of a page and keeps a line's height; the rest of the space owed stays above that line, so Word breaks the page where it did, and the gap between the paragraph's lines comes off the line as it would off its space above. A paragraph in a table cell, an overlay or a list is left to its container |
 | Lists | Real Word lists: a `numbering.xml` definition per list, `w:numPr` on each item, and the authored marker as the level's text. Nesting is a list level, so Enter continues the list and Tab demotes an item. See "What a list becomes" below for the kinds that stay plain paragraphs |
-| Tables | Word tables, one cell per cell. Each cell states its own padding, on all four sides, so a row is as tall as the page draws it: as `w:tcMar`, and above and below partly in its paragraphs. Word and LibreOffice give every cell of a row the largest top and bottom margin of any cell in it, so a row's cells are written with its smallest, and the rest of a cell's padding above and below is space above its first paragraph and below its last (measured: a row whose day cells were padded 5.5pt above and 10.25pt below beside a label padded 0.75pt stood 60.3pt tall in both editors, where its tallest cell came to 46). A cell opening with a table has no paragraph above it to hold its padding, and a cell in a vertical merge has its bottom edge in another row: these keep their margins, and the row's comes down no lower than the largest of them. Its padding above and below gives up the room Word makes for the table's horizontal rules — half of a rule between two rows to each, the lower row's rule where the two differ, the rule above the table and the one below it whole to their row — which the page does not (measured: a 0.75pt rule made each row 0.75pt taller). A cell that holds nothing but an empty line — a row that is only a rule, its thickness the empty cell's font — has that line cut to the room its row leaves it, the page's row less the cell's own margins and border: the page draws the rule's borders across the line, and Word and LibreOffice keep them outside it and grow the row (measured: `CobaltRota`'s two rules under a 0.9pt border stood 0.9pt taller each). A line with letters, a picture or a paragraph border of its own keeps its height. A table that states no rule is written with the engine's default 1pt black rule, as the page draws it, not left on Word's thinner grid. Its `textAnchor` becomes `w:vAlign` and the paragraph's `w:jc`, with the engine's default — the vertical middle, on the left — where Word's is the top, so a line beside a taller neighbour sits where the page puts it and an amount column stays right-aligned. A cell with no style of its own is set in the engine's default cell face rather than the document's Normal. A cell's lines are one paragraph with line breaks; when its style's `lineSpacing(...)` is above zero and it has more than one line, they are a paragraph each, with the spacing after every line but the last, since Word has no space between the lines of one paragraph but a taller line. A column sized to its content gets a point more than the page gives it, so the editor's font substitute cannot wrap its widest cell. The width is written when the document states one or every column is fixed; otherwise Word sizes the table — see "What falls back". A table breaks across pages where the layout breaks it: every row the layout placed is kept whole (`w:cantSplit`), `repeatHeader(n)` rows repeat on each page (`w:tblHeader`) and stay with the row under them. Two tables in a row — rows included, since a row is carried as a table — are kept apart by a paragraph a tenth of a point tall, holding the rest of the gap between them: an editor joins two tables with nothing between them into one. A table or a row the layout moves to a new page keeps its own top edge there, as the page does — written as a line that tall, kept with it, since Word drops a paragraph's space above at the top of a page — while the gap between it and the block before stays at the foot of the page above, where it fits there; a gap the layout carries onto the new page, because it did not fit at the foot of the page above, is not yet held above a table (body paragraphs and spacers: see their rows) |
+| Tables | Word tables, one cell per cell. Each cell states its own padding, on all four sides, so a row is as tall as the page draws it: as `w:tcMar`, and above and below partly in its paragraphs. Word and LibreOffice give every cell of a row the largest top and bottom margin of any cell in it, so a row's cells are written with its smallest, and the rest of a cell's padding above and below is space above its first paragraph and below its last (measured: a row whose day cells were padded 5.5pt above and 10.25pt below beside a label padded 0.75pt stood 60.3pt tall in both editors, where its tallest cell came to 46). A cell opening with a table has no paragraph above it to hold its padding, and a cell in a vertical merge has its bottom edge in another row: these keep their margins, and the row's comes down no lower than the largest of them. Its padding above and below gives up the room Word makes for the table's horizontal rules — half of a rule between two rows to each, the lower row's rule where the two differ, the rule above the table and the one below it whole to their row — which the page does not (measured: a 0.75pt rule made each row 0.75pt taller). A row held at the page's height is written less its margins and those rules too — a rule and a half in the first row and the last, two in a table of one row — since both editors read a row's written height as its cells' content (measured: held less one rule, a table ruled at 0.75pt stood 0.46pt taller in its first row and 0.36pt in its last). A cell that holds nothing but an empty line — a row that is only a rule, its thickness the empty cell's font — has that line cut to the room its row leaves it, the page's row less the cell's own margins and border: the page draws the rule's borders across the line, and Word and LibreOffice keep them outside it and grow the row (measured: `CobaltRota`'s two rules under a 0.9pt border stood 0.9pt taller each). A line with letters, a picture or a paragraph border of its own keeps its height. A table that states no rule is written with the engine's default 1pt black rule, as the page draws it, not left on Word's thinner grid. Its `textAnchor` becomes `w:vAlign` and the paragraph's `w:jc`, with the engine's default — the vertical middle, on the left — where Word's is the top, so a line beside a taller neighbour sits where the page puts it and an amount column stays right-aligned. A cell with no style of its own is set in the engine's default cell face rather than the document's Normal. A cell's lines are one paragraph with line breaks; when its style's `lineSpacing(...)` is above zero and it has more than one line, they are a paragraph each, with the spacing after every line but the last, since Word has no space between the lines of one paragraph but a taller line. A column sized to its content gets a point more than the page gives it, so the editor's font substitute cannot wrap its widest cell. The width is written when the document states one or every column is fixed; otherwise Word sizes the table — see "What falls back". A table breaks across pages where the layout breaks it: every row the layout placed is kept whole (`w:cantSplit`), `repeatHeader(n)` rows repeat on each page (`w:tblHeader`) and stay with the row under them. Two tables in a row — rows included, since a row is carried as a table — are kept apart by a paragraph a tenth of a point tall, holding the rest of the gap between them: an editor joins two tables with nothing between them into one. A table or a row the layout moves to a new page keeps its own top edge there, as the page does — written as a line that tall, kept with it, since Word drops a paragraph's space above at the top of a page — while the gap between it and the block before stays at the foot of the page above, where it fits there; a gap the layout carries onto the new page, because it did not fit at the foot of the page above, is not yet held above a table (body paragraphs and spacers: see their rows) |
 | Composed cells (`DocumentTableCell.node(...)`) | Written by the same writers that write that node anywhere else, so a cell built from an image, a list or a table carries it. A nested table is a real `w:tbl` followed by the paragraph Word requires a cell to end with — a hairline, which the paragraph written next in the cell takes over, so no empty line opens under the table, and whose mark is hidden where it is left at the cell's end holding nothing and no space, since LibreOffice lays it out — and takes the width of the column it sits in — the column's, not the one the page gives it, because the layout reports a composed cell's content under the owner's path |
 | Inline chips (`inlineCode(...)`, `inlineChip(...)`, `highlight(...)`) | The chip's fill becomes the run's own `w:shd`, in a paragraph and in a list item alike. Its shape does not travel — see "What a chip keeps and loses" below |
 | Images | Embedded pictures at the node's declared size |