Map Ole2Frame as update-only with the embedded object preserved

Frame corners and the aspect lock are scriptable; the opaque storage and
envelope are excluded and refused on edit. The audit embeds a real PNG
through OCS's own builder and proves it survives DWG and DXF byte-for-byte.
Python creation stays a follow-up.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

plugins/opencad-python/README.md

@@ -94,7 +94,7 @@ The host-owned catalog classifies all 48 entity variants and tracks every
 traced field, including fields marked `unmapped`. Query it with
 `doc.coverage()` or `doc.coverage("Line")`; each row includes source field,
 type, access, and current validation status. Geometry edits remain limited to
-the 37 mapped kinds.
+the 38 mapped kinds.
 For any entity, `entity.snapshot` returns a detached dictionary of its raw
 CAD fields, including `snapshot["common"]` and kind-specific nested values.
 It can inspect an unmapped kind; editing the dictionary does

plugins/opencad-python/entity_manifest.json

@@ -36,7 +36,8 @@
     "Underlay",
     "Viewport",
     "ViewBorder",
-    "Light"
+    "Light",
+    "Ole2Frame"
   ],
   "manual_kinds": [
     "Dimension"
@@ -780,6 +781,32 @@
           "required": true
         }
       }
+    },
+    "Ole2Frame": {
+      "update_only": true,
+      "update_only_message": "Ole2Frame cannot be created from a script: its embedded object storage is opaque; existing frames can be moved, resized and aspect-locked, and the stored object is preserved untouched",
+      "fields": {
+        "storage": {
+          "exclude": true,
+          "_comment": "Opaque compound-file payload; snapshot-readable and preserved untouched."
+        },
+        "envelope": {
+          "exclude": true,
+          "_comment": "Opaque frame envelope; preserved untouched."
+        },
+        "version": {
+          "read_only": true
+        },
+        "source_application": {
+          "read_only": true
+        },
+        "ole_object_type": {
+          "read_only": true
+        },
+        "dwg_mode": {
+          "read_only": true
+        }
+      }
     }
   }
 }

plugins/opencad-python/src/ocs_module.rs

@@ -4780,7 +4780,7 @@ mod tests {
                 );
             }
         }
-        assert_eq!(emitted.len(), 37);
+        assert_eq!(emitted.len(), 38);
     }
 
     #[cfg(feature = "experimental-host-model")]