fix(docx): even a table row's vertical cell margins, and hold a composed chip to its outline

[DemchaAV]

Why

In Word, CobaltRota stood 23pt off its page on median and ran onto a second page.

• The cause, measured in both Word and LibreOffice: a table row gives every cell the largest top margin of any cell in it, and the largest bottom margin.
  • 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. Its tallest cell, content and padding, came to 46.
  • CobaltRota's masthead row stood 20.8pt taller than the page's.
  • Each staff row, its name padded 2.55pt against its days' 1.35, stood 2.4pt taller.
• A second defect in the same rota: a shift chip is a shape composed in a table cell and written as a panel. It has no layout placement, so its row was not held to its height. The chips closed round their line of text: most of the 17.5pt chips to 12.7pt.

What changed

• evenTheRowsMargins, called in writeTableRows once a row's cells are written and before holdRowHeight:
  • Each cell's top and bottom w:tcMar is lowered to the row's smallest.
  • The rest of the padding is written as w:before on the cell's first paragraph and w:after on its last.
  • Some cells keep their margin on a side: a cell opening with a table has no paragraph above it, and a cell in a vertical merge has its bottom edge in another row. The row's margin then comes down no lower than the largest margin such a cell keeps, so the cells beside it are not padded twice.
  • holdRowAtLeast still subtracts the row's margins, now the smaller ones. The moved spacing is part of the content, so the held height comes out the same.
• dropTheSpaceBelow is unchanged. It leaves a table with a drawn bottom alone, and every table writeTableRows writes has one (POI's single table border), so the padding moved below a last row's text is never stripped at the end of a page.
• writePanelPiece. A ShapeContainerNode written as a panel with no layout placement, which means composed in a table cell, is held at least its outline's height. This matches how panelWidth already takes the outline's width.
  • Tiles holding only drawing are not panels (writtenAsAPanel), so MeteredInvoice's rows, the case fix(docx): write a filled pill composed in a table cell as a panel, so a rota's shift chips keep their colour #772 guarded, are unaffected.
• Docs. CHANGELOG.md and docs/recipes/docx-export.md (the Tables row and the composed-shape paragraph) are updated.

Verification

• Full reactor gate: ./mvnw -B -ntp clean verify -pl :graph-compose-core,:graph-compose-render-pdf,:graph-compose-render-docx,:graph-compose-render-pptx,:graph-compose-templates,:graph-compose-testing,:graph-compose-qa,:graph-compose-coverage -am gives BUILD SUCCESS (1791 + 127 tests).
  • After install, examples run 93 green.
  • The knowledge checks and extract-api --check pass.
  • render-docx runs 706 tests.
• DocxCellPaddingTest:
  • New: a row's cells share its smallest top and bottom margins, and each cell's own padding sums back from margin plus paragraph spacing.
  • New: a cell opening with a table keeps its margin, and the 3pt cell beside it gets no padding written twice.
  • New: a cell in a vertical merge keeps its margins, with nothing written below it.
  • New: a cell in a vertical merge holds the row's bottom up to its own, so a 6pt cell beside it is left as it was.
  • New: the nested table's cell keeps its 5pt.
  • Changed: the padding cascade is asserted as margin plus the first paragraph's spacing.
• DocxComposedCellTest: the pill test now pins its row held at least the outline's 14pt, where fix(docx): write a filled pill composed in a table cell as a panel, so a rota's shift chips keep their colour #772 had pinned it not held.
• Each rule fails its own test when reverted: the evening, the top and bottom floors at the kept margins, the vertical-merge exclusion, and the outline hold.
• Template corpus (62 documents), against 2.5-dev:
  • Two documents change: CobaltRota and OrangeOps (unchanged in both editors).
  • CobaltRota's median drift falls from 23.1pt to 8.9 in Word and in LibreOffice.
  • CobaltRota fits one page again in LibreOffice; in Word its last staff row still goes onto a second page.
  • On that second page in Word, the repeated header stands where it does on the first, to within 0.1pt, so the padding moved into its cells' paragraphs is kept.
  • In Word, 62 of its 67 chips are 17.5pt, as on the page; before, they were 12.7 to 16.1pt.

Known limits

• Still left in CobaltRota in Word (about 9pt, one row onto page 2):
  • The masthead subtitle's -6.5pt top margin inside a composed cell has no space above it to come out of.
  • A stacked chip's 10pt line stands in a 9.2pt chip.
  • The group icons are anchored a row low.
• Each of these is its own mechanism.

Lane: shared-engine (render-docx). No public API change.