feat: read concrete-lining drawings 04-004..009 and link lining spec to model (Task 6)

Extracted per-sheet pattern groups (입출구부 50 m / 온도미고려), note-5 scope,
fck 27 MPa, SD400, aggregate 25 mm, rebar label counts and printed radii.
Model keeps R1 = 6,982 mm; lining sheets print 6.892 m -> [CONFLICT DETECTED]
for user check. Sheet-to-station and pattern-name mapping left [미확정].
Viewer shows the lining spec on click.

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

scripts/explore_lining.py

@@ -0,0 +1,89 @@
+#!/usr/bin/env python3
+"""Explore the concrete-lining structure drawings (04-004 .. 04-009).
+
+Read-only on the source RAG folder. For each DXF prints layers with entity
+counts, INSERT block names, dimension measurements and every text string with
+its position, and writes a JSON dump for later use.
+Usage: explore_lining.py <RAG_04_DIR> <OUT_JSON> [max_texts_per_file]
+"""
+import collections
+import glob
+import json
+import os
+import sys
+
+import ezdxf
+from ezdxf import recover
+
+RAG_04 = sys.argv[1]
+OUT_JSON = sys.argv[2]
+MAX_TEXT = int(sys.argv[3]) if len(sys.argv) > 3 else 400
+
+
+def load(path):
+    try:
+        return ezdxf.readfile(path), None
+    except Exception as exc:
+        try:
+            doc, _ = recover.readfile(path)
+            return doc, f"recovered after strict error: {type(exc).__name__}"
+        except Exception as exc2:
+            return None, f"{type(exc).__name__} | recover: {type(exc2).__name__}: {exc2}"
+
+
+def explore(path):
+    rec = {"file": os.path.basename(path)}
+    doc, note = load(path)
+    if doc is None:
+        rec["error"] = note
+        return rec
+    rec["note"] = note
+    msp = doc.modelspace()
+    layers = collections.Counter()
+    counts = collections.Counter()
+    for e in msp:
+        counts[e.dxftype()] += 1
+        layers[e.dxf.layer] += 1
+    rec["layers"] = dict(layers.most_common())
+    rec["entity_counts"] = dict(counts.most_common())
+    rec["inserts"] = dict(collections.Counter(e.dxf.name for e in msp if e.dxftype() == "INSERT").most_common(30))
+    dims, texts = [], []
+    for e in msp:
+        t = e.dxftype()
+        if t == "DIMENSION":
+            try:
+                val = round(float(e.get_measurement()), 3)
+            except Exception:
+                val = None
+            dims.append({"layer": e.dxf.layer, "value": val, "text": e.dxf.get("text", "")})
+        elif t in ("TEXT", "MTEXT"):
+            s = e.dxf.text if t == "TEXT" else e.plain_text()
+            if s and s.strip():
+                pos = e.dxf.insert
+                texts.append({"layer": e.dxf.layer, "x": round(pos.x, 2), "y": round(pos.y, 2),
+                              "text": s.strip().replace("\n", " | ")[:200]})
+    rec["dimensions"] = dims[:200]
+    rec["texts_total"] = len(texts)
+    rec["texts"] = texts[:MAX_TEXT]
+    return rec
+
+
+def main():
+    files = sorted(glob.glob(os.path.join(RAG_04, "C0060304-00[4-9]*.dxf")))
+    out = [explore(f) for f in files]
+    with open(OUT_JSON, "w", encoding="utf-8") as fh:
+        json.dump(out, fh, ensure_ascii=False, indent=1)
+    for r in out:
+        print("==", r["file"])
+        if "error" in r:
+            print("  ERROR", r["error"])
+            continue
+        print("  note:", r["note"])
+        print("  entities:", r["entity_counts"])
+        print("  layers:", dict(list(r["layers"].items())[:25]))
+        print("  inserts:", r["inserts"])
+        print("  dims:", len(r["dimensions"]), "texts:", r["texts_total"])
+
+
+if __name__ == "__main__":
+    main()