feat(refs): xrefs, raster underlays, data extract and real DWG output

SECTION 24 completes at eleven tools with xref_attach, xref_manage,
image_attach, data_extract and drawing_export_dwg, on the four contract members
that genuinely differ per engine -- backends/contracts/refs.py. Everything else
in the sheet track composes the generic members and is written once.

The ActiveX members were read off the AutoCAD 2026 seat's own type library
(C:\Program Files\Common Files\Autodesk Shared\acax25enu.tlb, "AutoCAD 2025
Type Library" 1.0, the library the running 25.x seat registers) before a line of
the COM path was written, and the measurement is in the code beside the calls:

  IAcadModelSpace.AttachExternalReference(PathName, Name, InsertionPoint,
      Xscale, Yscale, Zscale, Rotation, bOverlay, Password)
  IAcadModelSpace.AddRaster(imageFileName, InsertionPoint, ScaleFactor,
      RotationAngle)
  IAcadBlock: IsXRef (get), Path (get AND put -- so the repath is an assignment,
      not a method), Reload(), Unload(), Bind(bPrefixName), Detach(),
      XRefDatabase (get)
  IAcadDocument.SaveAs(FullFileName, SaveAsType, vSecurityParams)
  AcSaveAsType: ac2000_dwg=12 ac2004_dwg=24 ac2007_dwg=36 ac2010_dwg=48
      ac2013_dwg=60 ac2018_dwg=64 (=acNative)

The running seat itself was not answering COM while this landed (its window was
Not Responding and GetActiveObject never returned), so the type library -- which
is the same seat's declared surface and reads without a call into the process --
is what the members are measured from; no document of the operator's was opened
or touched. This repository has been bitten four times by a fake that invented a
member, so the COM fakes in the tests model those names and nothing else.
ActiveX angles are radians, so the degree-to-radian conversion happens at that
boundary and nowhere else.

Headlessly, ezdxf.xref.attach carries the attachment (measured on ezdxf 1.4.4:
block flags 20 for an attachment and 24 for an overlay, so "is this an xref" is
flags & (BLK_XREF | BLK_XREF_OVERLAY) -- masking BLK_XREF alone misses every
overlay), add_image_def + add_image the raster, with Pillow reading the pixel
size so the placed image keeps the file's aspect.

Three capability keys, declared in both maps:

  dwg_write  -- measured absent here (odafc.is_installed() is False), so the
                ezdxf entry is a runtime re-evaluation like viewport_render's
                matplotlib check rather than a hardcoded False: installing the
                ODA File Converter starts the call working with no edit to the
                map. The refusal names the install route and drawing_export_dxf.
  xref_live  -- reload and bind need a live seat's xref manager and are refused
                headlessly; list, detach and path are headless and are not
                behind the key.
  xlsx_write -- openpyxl is optional and absent here; CSV is always available,
                so the refusal never blocks the deliverable and says so.

Two numbers the plan predicted wrongly are corrected to what the registry
actually does. `block` outranks `drawing` in _GROUP_TAG_PRIORITY, so the two
xref tools file under `blocks` (9 -> 11) beside block_insert -- which is where
an xref belongs, being a block definition that lives in another file -- and
`drawing` moves 11 -> 12, not 11 -> 14. And `data_extract` must not say "parts
list" in its own text: that is the golden discovery query for
entity_create_table, and a file writer outranking the tool that draws the thing
is a regression the tuning bar catches. It is described by its destination --
a file -- instead.

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

discovery/aliases.py

@@ -1027,6 +1027,66 @@ TOOL_ALIASES: dict[str, ToolAliases] = {
             "pozisyon numarasi",
         ),
     ),
+    "xref_attach": ToolAliases(
+        acad=("XATTACH",),
+        synonyms=(
+            "attach an xref",
+            "external reference",
+            "xref",
+            "reference another drawing",
+            "overlay a drawing",
+            "harici referans",
+        ),
+    ),
+    "xref_manage": ToolAliases(
+        acad=("XREF", "XBIND"),
+        synonyms=(
+            "list the xrefs",
+            "reload an xref",
+            "bind an xref",
+            "detach an xref",
+            "repath an xref",
+            "xref manager",
+            "broken xref path",
+        ),
+    ),
+    "image_attach": ToolAliases(
+        acad=("IMAGEATTACH",),
+        synonyms=(
+            "attach an image",
+            "raster underlay",
+            "insert a png",
+            "background image",
+            "scanned drawing",
+            "resim ekle",
+        ),
+    ),
+    "data_extract": ToolAliases(
+        acad=("DATAEXTRACTION", "EATTEXT"),
+        synonyms=(
+            # Not the bare phrase "parts list": that is the golden query for
+            # `entity_create_table`, and a file writer must not outrank the
+            # tool that draws the thing. This one is asked for by its
+            # destination -- a file -- which is what distinguishes it.
+            "export the bill of materials",
+            "extract attributes",
+            "bom to csv",
+            "bom to excel",
+            "data extraction",
+            "excele aktar",
+        ),
+    ),
+    "drawing_export_dwg": ToolAliases(
+        acad=("SAVEAS",),
+        synonyms=(
+            "export dwg",
+            "save as dwg",
+            "write a dwg",
+            "autocad 2018 format",
+            "downgrade to r2000",
+            "dwg olarak kaydet",
+        ),
+    ),
     # ── Layers & linetypes ──────────────────────────────────────────────────
     "layer_create": ToolAliases(
         acad=("LAYER", "LA"),