Parameters: unit-aware parameters (an inch parameter reads bare numbers as inches), atan2/mod/trunc and clearer unit errors, cycle paths (a → b → a), rename with every reference following (expressions, feature inputs, dimensions, favourites, comments), deletes refused with the list of users, parameter errors shown on the features using them, parameters.add/rename/delete/comment/users/graph/complete and expr.evaluate; ChangeParameterCommand renames and favourites; hostile test no longer writes stray files

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

crates/engine/src/tests.rs

@@ -288,6 +288,12 @@ fn hostile_params_never_panic() {
         "datum",
         "tolerance",
         "face",
+        "new_name",
+        "favorite",
+        "favorites",
+        "filter",
+        "kind",
+        "prefix",
     ];
     let mut internal = Vec::new();
     for spec in command_specs() {
@@ -299,6 +305,9 @@ fn hostile_params_never_panic() {
         }
         for v in hostile_values() {
             for k in keys {
+                if k == "path" && spec.id.starts_with("parameters.") {
+                    continue; // parameter files: covered by their own tests (no stray files)
+                }
                 let mut s = Session::default();
                 // A model with a sketch, a body and an active sketch, so most commands get far.
                 let _ = s.execute("PrimitiveBox", &json!({"length": 10, "width": 10, "height": 10}));