ours: наш оверлей к апстриму 1.5.1 (дельта для переноса в 1.6.0)

10 изменённых файлов + 2 новых (engineering/gost_titleblock.py, _fonts/isocpeur.ttf).
Ветка-донор для трёхстороннего переноса в ours-1.6.

backends/contracts/layouts.py

@@ -28,6 +28,29 @@ class LayoutContract(ABC):
         """Activate a layout tab ('Model' or a paper-space layout name)."""
         ...
 
+    # MCP card t_b950b5c4 (01.10.2026). A sheet's format is part of the page
+    # setup, and every plot of the sheet reads it: without a way to state the
+    # format, a 210x297 frame drawn on a layout that still says A3 exports onto
+    # A3 with the frame in a corner. The headless backend stores it in the
+    # layout's paper fields; ActiveX exposes no verified equivalent.
+    @capability(  # noqa: B027
+        "paper_space",
+        reason=(
+            "ActiveX has no verified member for a layout's sheet format (the page setup lives in "
+            "the drawing's plot configuration, which has not been exercised against a live "
+            "AutoCAD). Set the format in AutoCAD's Page Setup, or use the headless backend "
+            "(AUTOCAD_MCP_BACKEND=ezdxf), where layout_create + layout_set_paper store it."
+        ),
+    )
+    async def layout_set_paper(self, name: str, width: float, height: float) -> dict:
+        """Set the sheet a layout is set up for, in millimetres.
+
+        Returns ``{ok, layout, paper_mm}``. This is what
+        ``drawing_export_pdf(page_size='layout')`` reads to size the page, so a
+        sheet exported at 1:1 is the format it was drawn for.
+        """
+        ...
+
     @abstractmethod
     async def layout_delete(self, name: str) -> dict:
         """Delete a paper-space layout and everything drawn on it.