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/test_phase3_artifact_checker.py

@@ -26,6 +26,33 @@ def sha256(path: Path) -> str:
     return hashlib.sha256(path.read_bytes()).hexdigest()
 
 
+def valid_dataset_item() -> dict[str, object]:
+    return {
+        "schema": "phase3_dataset_item_v1",
+        "item_id": "DI-000001",
+        "participant_key": "PX-0001",
+        "session_key": "SX-0001",
+        "turn_key": "TX-000001",
+        "persona_id": "P1",
+        "stage": "rapport",
+        "speaker": "client",
+        "text_masked": "요즘 [NAME] 관련 고민이 있습니다.",
+        "techniques": [],
+        "client_states": [],
+        "feedback_scores": [],
+        "supervisor_comments": [],
+        "source_refs": {
+            "session_started_at": "2026-06-27T00:00:00Z",
+            "export_manifest_id": "phase3-fixture",
+        },
+        "privacy": {
+            "direct_identifiers_removed": True,
+            "pii_scan_status": "pass",
+            "consent_scope": "recursive_learning_seed",
+        },
+    }
+
+
 class Phase3ArtifactCheckerTests(unittest.TestCase):
     def make_root(self) -> Path:
         tmp = tempfile.TemporaryDirectory()
@@ -66,7 +93,10 @@ class Phase3ArtifactCheckerTests(unittest.TestCase):
             root / "04-privacy" / "privacy_audit.md",
             "# Privacy audit\n\nLegal/privacy reviewer: reviewer@example.invalid\n",
         )
-        write_text(root / "03-export" / "anonymized_dataset.jsonl", "{}\n")
+        write_text(
+            root / "03-export" / "anonymized_dataset.jsonl",
+            json.dumps(valid_dataset_item(), ensure_ascii=False, sort_keys=True) + "\n",
+        )
 
         metrics = {
             name: {
@@ -236,6 +266,33 @@ class Phase3ArtifactCheckerTests(unittest.TestCase):
 
         self.assertTrue(any("sha256 mismatch" in error for error in report.errors), report.errors)
 
+    def test_approved_manifest_rejects_malformed_dataset_jsonl(self) -> None:
+        root = self.make_root()
+        dataset_path = root / "03-export" / "anonymized_dataset.jsonl"
+        write_text(dataset_path, "{}\n")
+        manifest_path = root / "03-export" / "export_manifest.json"
+        manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+        manifest["files"][0]["sha256"] = sha256(dataset_path)
+        manifest_path.write_text(json.dumps(manifest), encoding="utf-8")
+
+        report = checker.validate(root, max_scan_rows=100)
+
+        self.assertTrue(any("dataset item missing keys" in error for error in report.errors), report.errors)
+
+    def test_dry_run_manifest_rejects_malformed_dataset_jsonl(self) -> None:
+        root = self.make_root()
+        dataset_path = root / "03-export" / "anonymized_dataset.jsonl"
+        write_text(dataset_path, "{}\n")
+        manifest_path = root / "03-export" / "export_manifest.json"
+        manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
+        manifest["export_status"] = "technical_dry_run"
+        manifest["files"][0]["sha256"] = sha256(dataset_path)
+        manifest_path.write_text(json.dumps(manifest), encoding="utf-8")
+
+        report = checker.validate(root, max_scan_rows=100)
+
+        self.assertTrue(any("dataset item missing keys" in error for error in report.errors), report.errors)
+
 
 if __name__ == "__main__":
     unittest.main()