feat(publish): S-4 pub_card_progress 발행 — 카드 SR 상태 read model (study→viewer)

DS 가 가진 카드 SR progress row 를 발행(kind=study_card_progress) = read model.
viewer C-4 복습큐/미확인 set-difference 재료. plan study-viewer-port S-4.
- projection: KIND_CARD_PROGRESS + project_card_progress(card_id·topic_id·last_outcome·
  last_reviewed_at·due_at·review_stage). ★ALL row(due_at NULL sentinel=암-on-new·terminal
  포함) — due-only 발행 금지(sentinel 누락→viewer 미확인 오분류).
- enqueue: enqueue_card_progress_publish + backfill_publish_card_progress(필터 없음).
- 훅: /study-cards/{id}/rate 의 rate_card 직후(같은 tx·flag 게이트). 단일 write 사이트.
  SR 계산=DS(sr_schedule 무변경), 발행=결과만.
- 카드 삭제 시 progress tombstone 안 함 = DS SR 보존(재승인 복원), orphan 은 viewer C-4 가 로컬 드롭.
- scripts/backfill_publish_card_progress.py.

py_compile PASS · project_card_progress 단위검증(sentinel due_at=None 보존).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/api/study_cards.py

@@ -28,7 +28,7 @@ from models.study_memo_card_progress import StudyMemoCardProgress, rate_card
 from models.study_question import StudyQuestion
 from models.user import User
 from services.study.card_normalize import compute_dedup_hash
-from services.study.publish_enqueue import enqueue_card_publish
+from services.study.publish_enqueue import enqueue_card_progress_publish, enqueue_card_publish
 
 router = APIRouter()
 
@@ -321,6 +321,9 @@ async def rate(
     if outcome is None:
         raise HTTPException(status_code=422, detail=f"invalid outcome: {body.outcome!r}")
     progress = await rate_card(session, card=card, outcome=outcome, now=datetime.now(timezone.utc))
+    # 카드 SR 상태 발행(같은 tx, flag off=no-op) — ALL row(sentinel/terminal 포함). S-4.
+    if settings.study_publish_enabled:
+        await enqueue_card_progress_publish(session, progress)
     await session.commit()
     return RateResult(
         card_id=card.id, outcome=outcome, review_stage=progress.review_stage, due_at=progress.due_at