M4.95: EMF and WMF open, place and paste as vector objects

crates/metafile import: EMF and WMF (placeable or not) records play on a
small device-context model (objects numbered as GDI does, saved DCs, world
transforms and mapping modes, path brackets, the current position) into one
artboard (the picture's frame) and one layer: paths with fills and strokes
(pens with caps, joins, dashes), clipping groups for clips, images from DIBs
(StretchDIBits, BitBlt, StretchBlt, AlphaBlend, StretchDIB, DIBBitBlt) and
point type in the font the file names. Lines drawn one after another join
into one path; a clip around the whole picture is dropped; objects far
outside it are left out; unknown records are skipped with one warning.

document.open and file.place read .emf and .wmf through the shared loader
(Open and Place filters list them). clipboard.importEmf loads a picture into
the clipboard, and Paste takes image/emf from a system clipboard service
ahead of text and bitmaps. The import fuzzer covers mutated and random-record
metafiles opened, placed and pasted.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/control-protocol.md

@@ -363,4 +363,5 @@ native files `version` and `preview`. A bad range keeps the dialog open; `ui.dia
 artboards' files.
 
 EMF and WMF: Export As… lists both formats (`file.exportAs {format: "emf"}` or `"wmf"`); they have no options
-dialog, so `ui.dialog.confirm` asks for the path and writes the file (one per artboard with Use Artboards).
+dialog, so `ui.dialog.confirm` asks for the path and writes the file (one per artboard with Use Artboards). Open and
+Place read `.emf` and `.wmf`; a paste of `image/emf` from a system clipboard service runs `clipboard.importEmf`.