[b-re-w]

Part of DarkPyonix/compose-rust#299 (renderer half: compose-rust #346).

• shadow: Vec<ShadowLayer> on Column, Row, Box, Card; CSS order, up to 8 layers, one Shadow modifier each in consecutive chain positions ahead of corners, shape and fill; shrinking lists clear freed positions.
• Chain positions after the shadows shift by 7 (MODIFIER_SLOTS 22 to 29).
• Builds on FR-42 (Shadow modifier). No SPEC change: an FR-39 commit was added and reverted pending owner approval. Pins compose-rust v0.0.3; rounded shadows need the next compose-rust release.

[b-re-w]

Covers FR-42.3 (compose-rust docs PR #350, criteria 7 and 8): the shadow list on Column, Row, Box and Card. Test fixed in 162b3b7 (two wrong expectations in my new tests).

[b-re-w]

인계 메모 (pF 세션 종료, 2026-10-26). 작업 브랜치는 모두 커밋, 푸시되어 있다. 머지 규칙: 이 PR이 고친다고 하는 것을 증명하는 체크가 현재 헤드에서 초록일 때만 머지한다.

상태: 체크 4개 통과. compose-rust #346(그림자)에 의존한다.
다음: #346 머지와 compose-rust 릴리스 뒤 핀을 맞추고 재확인 후 머지.

[b-re-w]

Landed via #178 (integration of open PRs, 2026-11-07).