회기 무발화 0턴 분리, 자기예측 락 불변식 및 TDD 회귀 검증 완료

apps/api/app/session_projection.py

@@ -0,0 +1,35 @@
+"""브라우저용 세션 projection이 공유하는 순수 도우미."""
+
+from __future__ import annotations
+
+from datetime import datetime, timezone
+from typing import cast
+
+from .services import state_machine
+from .stage_contract import StageLabel, stage_label as _normalize_stage_label
+from .store import InProcSession, TurnRecord
+
+LEARNER_VISIBLE_AI_ROLE = "counselor"
+
+# 전 주기(라포→정리) 기준 라포 만점: 마지막 전이 임계(개입→정리)를 100으로 본다.
+_FULL_CYCLE_RAPPORT = max(state_machine.STAGE_ADVANCE_RAPPORT.values())
+
+
+def stage_label(stage: object) -> StageLabel:
+    return cast(StageLabel, _normalize_stage_label(stage))
+
+
+def iso(ts: float | None) -> str | None:
+    if ts is None:
+        return None
+    return datetime.fromtimestamp(ts, tz=timezone.utc).isoformat(timespec="seconds")
+
+
+def learner_visible_turns(sess: InProcSession) -> list[TurnRecord]:
+    return sess.turns_visible_to(LEARNER_VISIBLE_AI_ROLE)
+
+
+def _rapport_percent(credit: float) -> int:
+    if _FULL_CYCLE_RAPPORT <= 0:
+        return 0
+    return max(0, min(100, int(round(float(credit or 0.0) / _FULL_CYCLE_RAPPORT * 100))))