세션 평가·라이브코치·교수자 분석 라운드 마감 + 문서 정리 + 코드품질 리팩터

- 누적 작업트리 커밋: 회기 평가 복구·durable 저장, 라이브 코치 이력/근거, 교수자 학생분석, 음성 비언어 메타, PII 마스킹, 운영 티켓/헬스 등
- 문서: 완료 기록 docs/archive/ 냉동 보관, docs/ 단일 인덱스(docs/README.md)+통합 TODO(docs/TODO.md)로 정리
- 리팩터(행위 보존): Stage enum SSOT(taxonomy 소유·state_machine re-export), store recent/masked_turns 중복 제거, speaker_ko_label 단일 헬퍼, _list_sessions N+1 제거(state/turns 배치 + 턴평가 하이드레이션 배치)
- 검증: 백엔드 pytest 352 passed, _list_sessions E2E chromium-single-run 2 passed

apps/api/app/turn_runtime.py

@@ -19,6 +19,9 @@ from .store import InProcSession, TurnRecord, store
 
 logger = logging.getLogger(__name__)
 
+_LIVE_COACH_RECHARGE_MIN_RAPPORT = 0.35
+_LIVE_COACH_RECHARGE_MIN_OPENNESS_GAIN = 0.02
+
 
 class SessionAccessError(str, Enum):
     NOT_FOUND = "not_found"
@@ -179,6 +182,63 @@ async def record_safety_event(
         require_runtime_fallback_allowed("safety event")
 
 
+def should_recharge_live_coach_credit(
+    evaluation: dict | None,
+    before: state_machine.SessionState,
+    after: state_machine.SessionState,
+) -> tuple[bool, str]:
+    """Good-score recharge gate based on stored evaluator/state-machine evidence."""
+    if not isinstance(evaluation, dict):
+        return False, ""
+    if evaluation.get("appropriateness") != "pos":
+        return False, ""
+    try:
+        rapport = float(evaluation.get("rapport_signal") or 0)
+    except (TypeError, ValueError):
+        rapport = 0.0
+    if rapport < _LIVE_COACH_RECHARGE_MIN_RAPPORT:
+        return False, ""
+
+    openness_gain = float(after.effective_openness or 0) - float(before.effective_openness or 0)
+    stage_changed = after.stage != before.stage
+    if not stage_changed and openness_gain < _LIVE_COACH_RECHARGE_MIN_OPENNESS_GAIN:
+        return False, ""
+    if stage_changed:
+        return True, "좋은 발화로 내담자 단계가 열려 코칭 기회 1개를 충전했습니다."
+    return True, "좋은 발화 뒤 내담자 개방도가 올라 코칭 기회 1개를 충전했습니다."
+
+
+async def maybe_recharge_live_coach_credit(
+    sess: InProcSession,
+    ctx: orchestrator.TurnContext,
+    result: orchestrator.TurnResult,
+) -> None:
+    """Record one live-coach recharge when a strong learner turn changes client state."""
+    assert ctx.state_after is not None
+    should_recharge, reason = should_recharge_live_coach_credit(
+        result.evaluation,
+        ctx.state_before,
+        result.state_after,
+    )
+    if not should_recharge:
+        return
+    try:
+        await session_persistence.record_live_coach_recharge(
+            session_id=sess.session_id,
+            learner_id=sess.learner_id,
+            turn_seq=result.turn_seq,
+            stage=stage_label(result.state_after.stage),
+            reason=reason,
+        )
+    except Exception:
+        logger.exception(
+            "live coach recharge persistence failed: session_id=%s turn_seq=%s",
+            sess.session_id,
+            result.turn_seq,
+        )
+        require_runtime_fallback_allowed("live coach recharge")
+
+
 async def finalize_completed_turn(
     sess: InProcSession,
     ctx: orchestrator.TurnContext,
@@ -195,6 +255,7 @@ async def finalize_completed_turn(
         context_prefix=context_prefix,
         counselor_turn=counselor_turn,
     )
+    await maybe_recharge_live_coach_credit(sess, ctx, result)
     await record_safety_event(sess, ctx, result)
 
 
@@ -203,8 +264,10 @@ __all__ = [
     "append_completed_turn",
     "finalize_completed_turn",
     "load_owned_session",
+    "maybe_recharge_live_coach_credit",
     "record_safety_event",
     "record_completed_turn",
+    "should_recharge_live_coach_credit",
     "stage_label",
     "update_session_state",
 ]