feat(layout): leave less sure line caches for Hancom to lay out

[airmang]

Summary

Stacked on #497. Merge it after #499 and #498, which fix line breaks that these guards alone cannot catch.

Hancom Office takes a cached paragraph's line breaks, line heights, baseline and tab widths as written. A cache whose breaks differ from Hancom's makes it press the text of a line together. This PR leaves every paragraph whose cache is less sure for Hancom to lay out:

• Close to a line's end. A paragraph whose lines break elsewhere once every line is laid out 100 HWPUNIT narrower or wider.
• Close to a tab stop. A paragraph whose text before a tab is closer to a tab stop than a layout unit (4 HWPUNIT) for each character since the line's start or the last tab stop, at most 100 HWPUNIT. A tab right after another starts exactly at a stop and needs no margin.
• Faces and looks not seen on the desktop. A paragraph in a face Hancom may draw in another (one not installed, a name no table lists), or one holding bold characters in a 한양 face (Hancom draws them a twentieth of an em wider) or in HCI Hollyhock. Also one at 장평 outside 50 to 200 %, 자간 outside -30 to 30 %, or 최소 공백 over 50 %, and one holding a no-break space with 최소 공백 or 자간. Also one holding a glyph whose advance comes from the font file only, not from Hancom's layout, or a page control among its text.
• Odd text height at the centre. A paragraph whose characters sit at the centre of their line, when its text height is odd: which way Hancom rounds the half was not seen.

Three values are also written as Hancom writes them:

• Baseline for each vertical alignment. 0 for characters set at the top of their line, half the text height at the centre and all of it at the bottom, besides 85 % on the baseline.
• Captions in a table's line. A caption above or below a table set as a character takes its lines and its gap in the table's line, and one beside it none. The line holds the caption only when the caption's paragraphs are laid out surely.
• Paragraph end height. A larger empty run ending the paragraph makes the last line's text as tall as itself, not only the line.

The changelog entry for the experimental line caches is written out once. The stacked branches had left overlapping copies of its sentences.

Test plan

• New tests for each guard fail before the change and pass after it
• Line cache tests, lint, format, type checks and the other repository gates

🤖 Generated with Claude Code

[airmang]

7464f61 검토 완료. 줄 폭 ±100 HWPUNIT/탭 경계 여유 검사, 글꼴·장평·자간·최소 공백의 보수적 제외, 세로 정렬별 baseline, 캡션과 큰 문단 끝 run의 높이 기록 및 문서 변경 범위를 확인했습니다. 이 head의 줄 캐시 테스트 44개는 통과했습니다. 다만 최종 CI 일부가 진행 중이고, 선행 #491·#495의 기존 미해결 P2가 이 최종 브랜치에서도 그대로 재현됐습니다: 큰 선행 컨트롤 run 사례는 작성 전 vertpos=3200, 작성 후 및 저장/재열기 후=1600이며, 다중 자식 ctrl 사례는 textpos=[0,86,156] 대신 [0,102,172]가 필요합니다. 기존 리뷰 문제를 중복 인라인 등록하지 않고 선행 문제 해결을 기다립니다. 또한 명시적 선행 수정 #499는 최신 main과 CHANGELOG 충돌 상태입니다. 선행 수정/병합과 최신 head CI·통합 재검증이 완료될 때까지 보류합니다.

[airmang]

Reviewed new head 0193e87 and its delta from the previously reviewed head. The expanded ratio/spacing/condense ranges, safe bold-face filter, and nonbreaking-space exclusions have corresponding tests. All 11 current checks pass; verified workflow head SHA and read CI logs (6,899 passed, 18 skipped, 1 xfailed plus lint/type/hygiene). Locally, all 52 line-cache tests pass.

Hold remains necessary for inherited unresolved #491 and #495 findings. Reproduced both on this exact head: writing/reopening caches changes the second paragraph's vertpos from 3200 to 1600 when a leading control run is 20pt and body text is 10pt; a ctrl wrapper containing colPr/header/footer yields textpos [0,86,156] instead of [0,102,172]. The new guards do not exclude or correct those cases. Existing inline findings on those dependency PRs remain applicable; no duplicate inline threads added. #499 has now merged, but #491/#495 must be fixed and their dependent stack revalidated before this PR can merge.