Merge pull request #1423 from felixriestra:pr/python-host-model

The bundled `opencad.python` plugin drives OCS through plugin API v7: all
43 canvas entity kinds, the drawing tables, and OCS's own commands run
step by step. RustPython stays in the plugin process — the plugin crate is
outside the workspace with its own lock file, so the application's own
dependencies are unchanged.

Reconciled with the plugin command work that landed as #1425, which the
branch was written before:

- Both added `impl Drop for PluginProcessInteractiveAdapter`, which git
  merges silently into two impls that do not compile. One body now
  cancels the command and then drops it from the runner, in that order: a
  plugin waiting on a step has to be released before the runner forgets
  the command.
- `execute_command` (#1425) and `run_command` (#1423) are both routes from
  a script to the command line, and only the second was guarded. The
  SCRIPTCOMMANDS switch and the denylist are shared now, so neither route
  is the unguarded one.
- `run_command` dispatched with plugin dispatch still enabled, so a script
  naming a plugin command re-entered the plugin that was blocked waiting
  for it. It sets the suppression flag for the length of the dispatch, as
  `execute_command` does.

The denylist read the command as typed, while the dispatcher resolves
aliases: a user-defined `Q` for `QUIT` (ALIASEDIT writes those) walked
past it. It resolves the alias first.

Also: the active-command comparison ran on every message, a mouse move
included, allocating two strings for names that are already `&'static
str`; SCRIPTCOMMANDS' own messages go through the translation macros; and
`docs/.DS_Store` (now ignored) and an unrelated RTF note about constraint
commands are out of the tree.

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

src/scene/entity.rs

@@ -543,6 +543,9 @@ impl Scene {
         let Some(existing) = self.document.get_entity(handle) else {
             return false;
         };
+        // IPC snapshots omit storage-only payloads (notably Unknown/Extended
+        // entities). Preserve them when replacing a clone from a plugin.
+        entity.preserve_storage_data_from(existing);
         // The caller edited a snapshot copy; keep the live entity in its block.
         entity.common_mut().owner_handle = existing.common().owner_handle;
 

src/scene/selection.rs

@@ -158,6 +158,16 @@ impl Scene {
         self.bump_selection_set();
     }
 
+    /// Script-facing replacement: preserve exactly the validated input order.
+    /// UI picks still use `select_entity` and its leader/annotation expansion.
+    pub(crate) fn replace_selection_exact(&mut self, handles: &[Handle]) {
+        if self.selected_handles_in_order() == handles { return; }
+        self.selected_constraint = None;
+        self.selected = handles.iter().copied().collect();
+        self.selected_order = handles.to_vec();
+        self.bump_selection_set();
+    }
+
     pub fn select_all_visible(&mut self) -> usize {
         let block = self.interaction_block_handle();
         let frozen: Option<HashSet<Handle>> = self