feat(settings): live COM smoke on AutoCAD 2026 builds the five .dwt twins and records the run

scripts/smoke_settings_com.py --build-dwt exited 0 on AutoCAD 2026 (25.1s),
2026-09-22: five templates/*.dwt written through drawing_template_save
(SaveAs code 66, each file opens with AC1032), page setup plotted and the
PDF's own /MediaBox read back as 420.158 x 297.039 mm, iso_a3_mech.dwt
reopened as source "bundled" with ISO-25 current, layer state / named view /
UCS / preferences / SummaryInfo / prompt line all through the COM engine.
The record is in CHANGELOG.md under Unreleased. The smoke keeps a ledger of
the documents it opens and closes them on the way out, so a failed run never
leaves scratch documents on the operator's seat. Two of its expectations
were corrected to the merged tree: mleaderstyle_create is implemented on COM
(spec: no `mleaderstyle` key), and plot_style_list marks catalogue rows with
`installed`. --interactive was not run unattended on the shared seat (an
unanswered GetPoint holds the command line); Task 23 measured the pick live.
*.dwt / *.dwg are binary in .gitattributes; AutoCAD's plot.log is ignored.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd

.gitattributes

@@ -2,3 +2,5 @@
 * text=auto
 templates/*.dxf text eol=crlf
 templates/*.dwt binary
+*.dwt binary
+*.dwg binary