fix(selection): clear selection when an interactive command ends

Editing tools (MOVE, COPY, STRETCH, ROTATE, OFFSET, SCALE, MIRROR) and
other interactive commands left their working set selected after they
finished, so the next edit silently reused it — confusing especially for
copy-producing tools. Drop the selection centrally in apply_cmd_result
when a command ends (active_cmd Some->None), excepting Relaunch/Dispatch
which hand a deliberate selection to a chained command. Pure-selection
commands run without an active command, so their result is preserved.

Closes #207

Co-Authored-By: Claude Opus 4.8 <[email protected]>

src/app/command_driver.rs

@@ -141,7 +141,34 @@ impl OpenCADStudio {
         }
     }
 
+    /// Applies one command result, then — when that result ended the active
+    /// command — drops the selection. Editing tools (MOVE, COPY, ROTATE, …) and
+    /// every other interactive command leave nothing selected once they finish,
+    /// so a follow-up edit doesn't silently reuse the previous working set.
+    ///
+    /// `Relaunch`/`Dispatch` are excepted: they end the front-end command only
+    /// to immediately start another and hand it a deliberate selection (the
+    /// pick-first selector relaunching MOVE on the picked set works this way).
+    /// Pure-selection commands (SELECTALL, QSELECT, …) run without an active
+    /// command, so `was_active` is false and their selection is preserved.
     pub(super) fn apply_cmd_result(&mut self, result: CmdResult) -> Task<Message> {
+        let was_active = self.tabs[self.active_tab].active_cmd.is_some();
+        let preserve_selection =
+            matches!(result, CmdResult::Relaunch(..) | CmdResult::Dispatch(..));
+        let task = self.apply_cmd_result_inner(result);
+        let i = self.active_tab;
+        if was_active
+            && !preserve_selection
+            && self.tabs[i].active_cmd.is_none()
+            && !self.tabs[i].scene.selected.is_empty()
+        {
+            self.tabs[i].scene.deselect_all();
+            self.refresh_properties();
+        }
+        task
+    }
+
+    fn apply_cmd_result_inner(&mut self, result: CmdResult) -> Task<Message> {
         let i = self.active_tab;
         match result {
             CmdResult::NeedPoint => {