feat(understand): room frames, the nearest panel and possible packages — what the field test asked for

The takeoffs were run again on a real P&ID pair (kept outside the repository)
and compared with the hand-made workbooks. The user chose how three gaps
should close:

- Rooms drawn as frames. A room label that no wall face holds takes the
  smallest closed, straight-sided polyline around it, provided it holds no
  other room number and is at least ten label heights a side (label+frame,
  0.8). A P&ID draws its rooms this way, so P&ID lengths are now cut at the
  frames rather than sent to the nearest label. An unnumbered mention inside
  a frame ('hot room') does not deny it.
- The nearest panel, flagged. cable_takeoff(panel_rule="nearest") is the
  default: a load that no callout places takes the nearest panel on the
  layout, among names with a panel prefix (is_panel_name: CP, JB, DB,
  MCC ...) or names a callout gives. The row is flagged panel_inferred, and
  an inferred panel never makes a package. panel_rule="stated" keeps the old
  behaviour. The takeoff_roundtrip gate and the cable correctness check read
  stated panels only: a guess is no evidence.
- Possible packages and detail copies. pipe_takeoff reports detail_copies:
  compact groups of tags drawn twice (repeated), and compact groups of one
  equipment's own parts, such as M150B, M150C and M150D of M150 (family). A
  vendor package or an equipment detail shows up this way. Nothing is
  removed until exclude_regions names a region. The runs left out go to the
  control rows as excluded_region and to excluded_m. The workbook's method
  sheet names the regions.

Each change has a synthetic test that failed first. Suite: 4986 passed, 1
xfailed. The inventory and the document numbers match (README: 4987
collected).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd

benchmarks/adapters/autocad_mcp_pro.py

@@ -837,7 +837,9 @@ class AutoCADMCPProAdapter(BenchmarkAdapter):
             if reasons:
                 pipe_mismatch.append({"run": run["id"], "reason": "; ".join(reasons)})
 
-        cable = {row["tag"]: row for row in cable_rows(pid, layout)["rows"]}
+        # panel_rule="stated": the gate reads what the drawing says; a nearest-panel
+        # guess is no evidence
+        cable = {row["tag"]: row for row in cable_rows(pid, layout, panel_rule="stated")["rows"]}
         cable_mismatch = []
         for want in truth["cable_rows"]:
             got = cable.get(want["tag"])

benchmarks/correctness_suite.py

@@ -915,7 +915,9 @@ async def cable_takeoff_roundup():
     truth = _plant_pair()
     rows = {
         row["tag"]: row
-        for row in cable_rows(read_snapshot(truth["pid"]), read_snapshot(truth["layout"]))["rows"]
+        for row in cable_rows(
+            read_snapshot(truth["pid"]), read_snapshot(truth["layout"]), panel_rule="stated"
+        )["rows"]
     }
     expected = {"M11": ("CP-1", 9), "T102": ("CP-1", 17), "M12": ("CP-2", 19), "T202": ("CP-2", 10)}
     for tag, (panel, metres) in expected.items():