Design properties: project, author and licence in the design, its exports and inspect_design (#1015) (#1189)

A design carries metadata (format 21): project, part number, revision, author, organization, description and license, plus other tools' data under reverse-DNS keys, kept as written. Edited in the Design Properties window (Document Settings), set by document.metadata.set, reported by inspect_design, and written into STEP, IGES and 3MF where the format has a place for them. Translated, with tests.

crates/mcp/src/tests.rs

@@ -242,6 +242,18 @@ fn parameters_drive_the_design() {
     assert!(d["params"].as_array().unwrap().iter().any(|p| p["name"] == "len" && p["value"] == 50.0), "{d}");
 }
 
+/// Design properties (#1015) are set through `execute` and come back in `inspect_design`.
+#[test]
+fn design_properties_show_in_inspect_design() {
+    let mut s = server();
+    let d = tool(&mut s, "inspect_design", json!({"measure": false, "sketches": false}));
+    assert_eq!(d["metadata"], json!({}), "{d}");
+    let params = json!({"values": {"author": "Agent", "com.example.agent": {"session": 7}}});
+    tool(&mut s, "execute", json!({"command": "document.metadata.set", "params": params}));
+    let d = tool(&mut s, "inspect_design", json!({"measure": false, "sketches": false}));
+    assert_eq!(d["metadata"], json!({"author": "Agent", "com.example.agent": {"session": 7}}), "{d}");
+}
+
 #[test]
 fn batch_stops_at_first_error_and_rolls_back() {
     let mut s = server();