[DemchaAV]

Why

Word makes room in a table's rows for its horizontal rules — half of a rule between two rows to
each, the rules above and below the table whole to their row — and the page draws them over the
cells' edges. clearOfTheRules takes that room off the cell's top and bottom padding; where the
padding is thinner than its share, it gives what it has and the row stood taller in Word, with
nothing in the report.

Measured in Word and LibreOffice on Windows — the paragraph under the table against the same table
unruled (an unruled table already sits ~2.65pt lower in both, a font-metric offset), to a tenth of
a point:

Table	Word	LibreOffice
4 rows, no padding, 3pt rules	+15.0	+15.0
4 rows, no padding, 1pt rules	+4.9	+5.0
4 rows, padding 1, 3pt rules	+7.0	+7.0
4 rows, padding 3, 3pt rules	0	0
3 rows, 2pt rules: two-line cell unpadded beside a one-line cell padded 2	+8.0	+8.0
the same, the two-line cell the padded one	0	0
2 rows, 2pt rules, padding 5 above and none below	+3.0	+3.0

The two mixed rows show how Word counts: each cell at its content and, on each side, its padding
or its share where that is more; the row at its tallest cell. A short cell whose padding falls
short beside a taller cell that sets the row adds nothing; "the most any cell holds beside the
tallest content" would have said 12 for the 8.

What changed

• DocxRuleRoom (new, package-private): counts each text cell of a row — count(row, placement, padding, round, textHeight) — and sums, row by row, what the tallest cell comes to past the
  page's height (taller). A row the layout does not tell the height of, or whose counted text it
  does not measure, counts the most its text cells' padding falls short of taking, and the note
  says "up to"; a header row repeated on every page counts once for each page the layout places it
  on.
• DocxSemanticBackend: ruleShareAbove/ruleShareBelow (shared with clearOfTheRules),
  roundTheContent (padding or share, each side), textHeight (the engine's own cell content
  height: lines × the measured line height plus their spacing), and nameTheRoomForTheRules —
  APPROXIMATED, subject cell rule: "…and sets the table about Xpt taller than the page".
• Not counted: cells built from a node and cells spanning rows; empty cells where the row is
  held at the page's height (their line is cut to the row's room, fitBlankLinesToTheRow). A cell
  of a space is written as a run and is counted. In the corpus's MerchantInvoice,
  ObsidianInvoice and CobaltRota, whose rows are built from nodes or hold empty cells and are
  ruled past their padding, the rows stood within half a point of the page's in Word, where
  counting those cells said 2–4pt.
• DocxNodeFieldLedgerTest: the cell paint entry names the case. Docs: the recipe's table row, the
  capability matrix's table row, CHANGELOG v2.5.0.

A row whose margins are evened to one a cell keeps (evenTheRowsMargins: a cell opening with a
table, or in a vertical merge) is counted as though each cell kept its own, which is not measured;
the Javadoc says so.

Verification

• ./mvnw -B -ntp test -f render-docx/pom.xml — DocxCellRuleRoomTest (new, 10, each with-layout
  case asserting the layout stood behind it): the measured tables above; a quarter-point rule
  (0.75pt in all); padding that takes the rules, no rules and the engine's defaults not named;
  line spacing part of a cell's height; a 2pt header over 0.5pt rows; a header repeated over pages
  counting again on each; cells built from a node and empty cells not counted, a cell of a space
  counted; a cell spanning rows not counted; a table composed in a cell and one with no layout
  named "up to", a composed table of node cells not at all. DocxRuleRoomTest (new, 5): a measured
  row, a row not told counting only itself at most, an unmeasured cell, an empty cell held and not,
  a row placed on three pages.
• 16 sabotages, each undoing one part — the note, the node and span exclusions, the room round the
  text, the measured branch, the bound, the threshold, padding past a share, the share between
  rows, a space, an empty cell where held and in the bound, the header's repeats, line spacing, an
  unmeasured cell, the bound for one row only — all caught.
• Corpus: 62/62 DOCX byte-identical; report notes 1246 → 1246.
• ./mvnw -B -ntp clean verify — BUILD SUCCESS (core 821, render-docx 1770, examples 93, qa 1820); the knowledge pack's --check
  passes.

Lane: render-docx (semantic backend) — a report note; no output change.