fix(styles): drop stale line caches when replace_font changes a paragraph's face

[airmang]

무엇

doc.styles.replace_font가 글꼴을 바꾼 뒤에도 본문 문단의 줄 배치 정보(hp:linesegarray)가 그대로 남았다. 한/글은 남은
정보의 줄 나눔을 그대로 따르므로, 새 글꼴의 글자가 옛 글꼴의 줄 폭에 맞춰 눌리거나 겹쳐 그려질 수 있었다.

• replace_font: 바꾸기 전과 뒤에 글자 모양(hh:charPr)마다 언어별 글꼴 이름을 비교해, 이름이 바뀐 글자 모양을 쓰는
  run이 있는 문단의 줄 배치 정보만 지운다. id만 다시 매겨진 글자 모양은 같은 글꼴을 가리키므로 건드리지 않는다.
• doc.parts.set_paragraph_auto_spacing: 한글·영문/숫자 자동 간격 값이 실제로 바뀌면 그 문단 모양을 쓰는 문단의 줄 배치
  정보를 지운다.
• 두 곳이 같이 쓰는 hwpx.oxml.header_fonts.clear_line_caches(document, char_pr_ids=..., para_pr_ids=...).

다른 문단의 줄 배치 정보는 그대로 둔다(한/글이 문서 전체를 다시 배치할 때 생기는 차이를 피한다).

시험

• tests/test_style_font_border_reads.py: 바뀐 글꼴의 문단만 정보가 지워지고 저장·다시 열기 뒤에도 그렇다. 다른 언어
  블록만 바꿀 때도 같다.
• tests/test_header_compat_authoring.py: 자동 간격 값이 그대로면 정보가 남고, 바뀌면 그 문단 모양의 문단만 지워진다.
• 세 시험 모두 고침 전에는 실패한다.

🤖 Generated with Claude Code

[airmang]

Exact head: b5839f5.

Reviewed before/after font-face resolution across language blocks, remapped font IDs, dirty/cache invalidation, direct-run paragraph selection, nested paragraph traversal, and the auto-spacing no-op/change path. The helper removes only direct paragraph line-cache children and marks changed sections for serialization. No unresolved code finding. All 104 local style/header compatibility tests passed, including save/reopen preservation and language-specific replacement.

All 13 current CI checks pass; verified successful workflow head SHA and read its test/lint/type/hygiene log (6,931 passed, 18 skipped, 1 xfailed; coverage 90.04%).

Merge held: after #505 merged, git merge-tree against current main 366e25d reproduces a content conflict in CHANGELOG.md. Preserve both entries when resolving against latest main, then revalidate the changed head and integration. No conflicted integration-test pass is claimed. COMMENT because this authenticated account owns the PR.

[airmang]

Reviewed exact head e7d6f44.

Range-diff confirms rebase/CHANGELOG placement only since the prior review. Rechecked face-name comparison across font renumbering/language blocks, direct paragraph-cache removal, section dirty marking and the auto-spacing change/no-op path. All 104 local style/header tests pass, including save/reopen preservation. No unresolved code finding. All 13 current CI checks pass; verified workflow head SHA and read its test/lint/type/hygiene log (6,932 passed, 18 skipped, 1 xfailed; coverage 90.04%).

Merge held: after #506 and #512 merged, git merge-tree against current main 73d68a7 reproduces content conflicts in CHANGELOG.md. Resolve preserving both PRs' changes and fixture coverage, then revalidate the updated head and combined tree. No conflicted integration-test pass is claimed. COMMENT because this account owns the PR.

[airmang]

Re-reviewed exact head dc04d89 against current main 73d68a7. Range-diff confirms only rebase/CHANGELOG placement changes. Rechecked face-name comparison across language blocks and font-ID renumbering, selective direct paragraph-cache removal, serialization dirty marking and auto-spacing change/no-op behavior. No unresolved finding; prior conflict is resolved.

All 104 local style/header compatibility tests pass, including font replacement save/reopen and unchanged-paragraph preservation. All 13 current checks pass; CI workflow head SHA verified and test/lint/type/hygiene logs inspected (6,935 passed, 18 skipped, 1 xfailed; coverage 90.05%). Tested head includes current main, tree 4c2bc0127e174735e64f55f97f44305563550ea0. Ready for expected-head-SHA squash merge. COMMENT because this account owns the PR.