fix(origin): return absolute icon path from SiloOrigin.icon()

The icon() method returned bare 'silo' which BitmapFactory could not
resolve. Return the absolute path to silo.svg so the C++ side can load
the icon directly.

freecad/silo_origin.py

@@ -9,6 +9,8 @@ delegating operations to the established Silo infrastructure while
 providing the standardized origin interface.
 """
 
+import os
+
 import FreeCAD
 import FreeCADGui
 from silo_commands import (
@@ -61,8 +63,10 @@ class SiloOrigin:
         return self._nickname
 
     def icon(self) -> str:
-        """Return icon name for BitmapFactory."""
-        return "silo"
+        """Return icon path for BitmapFactory."""
+        return os.path.join(
+            os.path.dirname(os.path.abspath(__file__)), "resources", "icons", "silo.svg"
+        )
 
     def type(self) -> int:
         """Return origin type (OriginType.PLM = 1)."""
@@ -388,9 +392,7 @@ class SiloOrigin:
 
             # Upload to Silo
             properties = collect_document_properties(doc)
-            _client._upload_file(
-                obj.SiloPartNumber, str(file_path), properties, comment=""
-            )
+            _client._upload_file(obj.SiloPartNumber, str(file_path), properties, comment="")
 
             # Clear modified flag (Modified is on Gui.Document, not App.Document)
             gui_doc = FreeCADGui.getDocument(doc.Name)