feat(layout): write the line of a paragraph holding a table, and the table's height

[airmang]

Stacked on #493.

Summary

• write_line_caches now also writes the single line of a body paragraph that holds only a table set as a character, the way Hancom Office writes it:
  • the line is as tall as the table's rows plus the table's outer margins;
  • the baseline sits at 85 % of that height;
  • the line is spaced the way the paragraph's characters are.
• The table's own height (hp:sz) is set to the height of its rows, which is the value Hancom saves. python-hwpx used to write the sum of the rows' least heights here.
• A row is as tall as its cells' lines, so the line is written only when every paragraph of the table's cells is one the function lays out surely; otherwise the paragraph is left for Hancom.
• New tests check that a paragraph holding a new table gets one line as tall as the table, and that a table with an emoji in a cell keeps its line for Hancom. The Hancom-saved form fixture also checks this paragraph's line against Hancom's.

Test plan

• The new test fails before the change and passes after it
• Lint, format, type checks and the other repository gates
• Full test suite: no new failures

🤖 Generated with Claude Code

[airmang]

d8dfbe946604ddfb8aacba46d1a276df156c7b6a에서 광고된 선행 브랜치 대비 diff와 글자처럼 놓인 표만 든 문단의 줄 높이와 hp:sz 기록 및 셀 측정 확실성 검사를 검토했습니다. 별도 체크아웃의 줄 캐시 회귀 테스트 17개가 통과했고, 정확한 head의 모든 CI 검사 및 Python 3.12 로그(6864 passed, 18 skipped, 1 xfailed; coverage 기준, Ruff·mypy·Pyright·공개 게이트 통과)를 확인했습니다. 이 PR 고유 변경에서 추가로 재현한 결함은 없습니다. 다만 이 브랜치는 미병합 #491에 연쇄 의존하며, 그 PR의 캐시 작성 후 문단 위치 변경 결함이 여전히 재현되고 리뷰 스레드도 미해결입니다. 선행 문제가 수정·병합된 뒤 최신 base/head와 통합 결과를 재검증할 때까지 보류합니다.