test: Step 3 cross-check of lining report and meta against raw DXF texts (Task 6)

19 checks: 6-sheet common values, 3-sheet temperature-exempt detail, 9 pattern
groups vs report rows, R1 6.982 vs 03-001 raw texts, thickness arithmetic,
output naming and version, meta content, no writes into RAG.
Report fix found by the check: SD400 label was missing; added.
Decision recorded: R1 = 6.982 m kept (user, 2026-10-21).

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A5Cun3RHQKna9qxE6ybZ4A

scripts/build_skeleton.py

@@ -192,7 +192,7 @@ meta = {
   "patterns": [{"from": a, "to": b, "pattern": pat} for a, b, pat, _ in ZONES],
   "open": ["4+700~4+745 and 5+480~5+500 excluded ([미확정])", "pattern zones (03-003~008) pending Task 5",
            "lining reference recorded (meta.lining_reference, 04-004~009); sheet-to-station mapping [미확정]",
-           "[CONFLICT DETECTED] lining sheets print R1=6.892 m, standard section R1=6,982 mm (model keeps 6.982) - user check"]
+           "[확정 2026-10-21] R1 6,982 mm 유지 (사용자 결정). 라이닝 도면 6장의 R1 6.892 m 표기는 확인 대상 오기로 기록", "pattern-group to excavation-pattern mapping: user explanation conflicts with filename (WL-4) - re-confirm [확인 필요]"]
 }
 _ls = json.load(open(f"{ROOT}/data/lining_spec.json", encoding="utf-8"))
 meta["lining_reference"] = {