chore(rebar): Pier_T_rebar 작업 폴더 초기 구성 및 외부 의존 파일 통합

- Code\rebar_pipeline, review_pipeline, pier-program을 정션에서 실제 폴더로 전환
- Code\rhino_mcp 및 CLAUDE_rhino배경.md 추가, .mcp.json은 PYTHONPATH로 새 위치 사용
- pier-program 내부 .git 제거(이력은 backup\pier-program_20261028.bundle에 보관)
- worktree 가이드 반영(CLAUDE.local.md, HANDOFF.md)
- D:\Rhino-MCP 경로 참조를 새 위치로 치환

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

Code/교각모델링앱/tools/test_store_concurrency.py

@@ -0,0 +1,45 @@
+"""Concurrency check of web/store.py wjson/rjson: one thread rewrites a job file while another reads it.
+
+Reproduces the 2026-10-12 E2E failure (reader saw an empty file during write_text). Pass = no read errors
+and no writer errors. usage: python test_store_concurrency.py [writes]
+"""
+import sys
+import tempfile
+import threading
+import time
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "web"))
+import store  # noqa: E402
+
+N = int(sys.argv[1]) if len(sys.argv) > 1 else 500
+p = Path(tempfile.mkdtemp()) / "G1_job.json"
+store.wjson(p, {"state": "대기", "log": []})
+stop = threading.Event()
+read_err, reads = [], [0]
+
+
+def reader():
+    while not stop.is_set():
+        try:
+            store.rjson(p)
+            reads[0] += 1
+        except Exception as e:
+            read_err.append(repr(e))
+
+
+t = threading.Thread(target=reader, daemon=True)
+t.start()
+write_err, t0 = [], time.time()
+try:
+    for i in range(N):
+        try:
+            store.wjson(p, {"state": "실행 중", "log": ["x" * 200] * (i % 50)})
+        except Exception as e:
+            write_err.append(repr(e))
+finally:
+    stop.set()
+    t.join(5)
+print(f"writes {N} reads {reads[0]} read_errors {len(read_err)} write_errors {len(write_err)} "
+      f"{time.time() - t0:.1f}s", read_err[:2], write_err[:2])
+sys.exit(0 if not read_err and not write_err else 1)