bench: matrix v6 adds arch_roundtrip; four architectural correctness checks; the live arch smoke

The evidence for track F, in the shape tracks A, E and B + G used.

- benchmarks/tasks_v6.py: 19 tasks, DEFAULT_MATRIX = "v6"; v5 to v2 stay
  addressable. arch_roundtrip draws the example plan with
  arch_plan_from_spec and reads it back without the spec: rooms_detect must
  find each labelled room within 0.1 % of its label and of the net floor
  computed by hand (4825 x 5750 and 3825 x 5750), the schedules must list
  D1, D2, W1, W2, and the plan is gated on a zero-issue critique and a
  finalize score of at least 90. A test removes one room label and the gate
  fails naming arch_room_unlabelled.
- Four correctness checks, every number worked out by hand in the docstring:
  L / T / X junction corners and wall areas, a 4 x 5 m room labelled 20.00 m2
  rather than its 21.84 m2 axis area, a door interrupting both faces, and a
  plan of plain lines read as 20 and 15 m2 at confidence 0.6. The published
  A/B report is re-run over 43 checks: 26 / 43 -> 43 / 43, zero regressed.
- scripts/smoke_arch_com.py runs the whole plan once on a live seat and
  closes every document it opens; the CHANGELOG records what it returned.
- The token suite measures a TOOL_PACKS=core,arch row; check_doc_numbers
  derives the task count from the v6 matrix; CLAUDE.md, both READMEs and
  the spec status line say what shipped.
- fix(com): the first live smoke exited 1 - the room reader found 0 wall
  segments. Measured on AutoCAD 2026 (2026-09-23): with a makepy cache,
  ModelSpace.Item(i) returns the gen_py IAcadEntity wrapper
  (type(item).__name__ == "IAcadEntity") and item.StartPoint on an
  AcDbLine raises AttributeError, so every entity_list row lost its
  type-specific properties (28 wall LINEs, 0 with start/end). _entity_info
  now re-dispatches exactly that wrapper through _com_unnarrow; after the
  fix 38 of 53 rows carry start/end and the smoke exits 0 with both rooms
  at 27 743 750 / 21 993 750 mm2 and 0 critique issues. Re-dispatch
  measured at ~1.7 ms per entity (dynamic vs gencache alike).

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

tests/test_token_suite.py

@@ -161,25 +161,36 @@ def test_the_cache_arithmetic_follows_the_published_multipliers():
 # -- lane 1: idle cost ------------------------------------------------------
 
 
-def test_the_idle_lane_covers_the_four_advertised_surfaces(report):
-    """Default, lean, search - and TOOL_PACKS=core,mech, the mechanical client
-    that never opens a P&ID, a live seat or a floor plan: the default surface
-    minus exactly the pid, settings and arch packs (track F added `arch`)."""
+def test_the_idle_lane_covers_the_five_advertised_surfaces(report):
+    """Default, lean, search - and the two single-vertical clients:
+    TOOL_PACKS=core,mech (the default surface minus exactly the pid and settings
+    packs, and the arch pack) and TOOL_PACKS=core,arch (minus pid, settings and
+    mech)."""
     variants = {row["variant"]: row for row in report["idle"]}
-    assert set(variants) == {"default", "lean", "packs_core_mech", "search"}
+    assert set(variants) == {"default", "lean", "packs_core_mech", "packs_core_arch", "search"}
     assert variants["default"]["advertised_tools"] > 100
     assert variants["lean"]["advertised_tools"] == len(server.LEAN_TOOL_NAMES)
     assert variants["search"]["advertised_tools"] == 2
-    dropped = sum(len(server.PACK_TOOL_NAMES[pack]) for pack in ("pid", "settings", "arch"))
+    packs = server.PACK_TOOL_NAMES
     assert variants["packs_core_mech"]["advertised_tools"] == (
-        variants["default"]["advertised_tools"] - dropped
+        variants["default"]["advertised_tools"]
+        - len(packs["pid"])
+        - len(packs["settings"])
+        - len(packs["arch"])
     )
-    assert (
-        variants["default"]["chars"]
-        > variants["packs_core_mech"]["chars"]
-        > variants["lean"]["chars"]
-        > variants["search"]["chars"]
+    assert variants["packs_core_arch"]["advertised_tools"] == (
+        variants["default"]["advertised_tools"]
+        - len(packs["pid"])
+        - len(packs["settings"])
+        - len(packs["mech"])
     )
+    for narrowed in ("packs_core_mech", "packs_core_arch"):
+        assert (
+            variants["default"]["chars"]
+            > variants[narrowed]["chars"]
+            > variants["lean"]["chars"]
+            > variants["search"]["chars"]
+        )
 
 
 def test_the_idle_lane_separates_the_wire_payload_from_what_the_model_pays(report):