test(qa): hold the Linux LibreOffice baseline to the lines #810 sets where the page does

[DemchaAV]

Why

#810 moved OrangeOps and NorthlineProposal nearer the page in LibreOffice on Linux. The committed Linux baseline still holds the old numbers. While it does, either document could slip back that far and the gate would stay green.

What changed

• libreoffice-linux.tsv and libreoffice-linux-lines.tsv are the measurement CI took on fix(docx): stand OrangeOps on one page in Word — room for a one-line heading, and a negative bottom edge kept #810's last commit (run 36935471879), unedited.

  Document	Pages	Lines found	Past 2pt	Median
  OrangeOps	2 → 1	6 → 99 of 108	5 → 0	3.87 → 0.32pt
  NorthlineProposal	2	131 → 132	33 → 5	0.44 → 0.28pt

• No other document's row changes.

• The header now names the LibreOffice build (420(Build:2)) where it said unknown.

Verification

• Not runnable locally. The Linux baseline is read only on Linux. The DOCX Fidelity (LibreOffice) job on this PR is the check: it measures the same tree against these files.

Lane: test (qa baselines).