feat(ui): feature-parity context menu — Snap Overrides, transparent Pan/Zoom, ARC keyword flow

The command menu now follows the commercial solutions' layout row for row: Enter, Cancel,
Recent Input ▸, the command's keywords, Snap Overrides ▸ (every object snap
with its glyph, Mid Between 2 Points, None, Osnap Settings…), then Pan and
Zoom. Pan / Zoom run transparently while a command is active ('PAN,
'ZOOM …): navigation modes leave the command untouched and an interactive
ZOOM Window parks it and resumes it afterwards. Rows carry an icon gutter
so labels align; the Enter row shows a default value ("<0.5000>") as its
hint instead of a second finish row.

ARC gets the commercial solutions' prompt flow with all keywords: start [Center], second
point [Center/End], end; after Center: end [Angle/chord Length]; after
End: center [Angle/Direction/Radius]; Enter continues tangent. The
previous default (Center/Start/End with method codes) stays as ARC_CSE.

Object snaps gain a one-shot "None" override. New strings in all locales.

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

src/app/command_driver.rs

@@ -920,6 +920,9 @@ impl OpenCADStudio {
         );
         let task = self.apply_cmd_result_inner(result);
         let i = self.active_tab;
+        // A transparent zoom that just finished hands control back to the
+        // command it interrupted before the "command ended" bookkeeping below.
+        self.resume_transparent_parent(i);
         let preview_hidden = self.tabs[i]
             .active_cmd
             .as_ref()
@@ -1394,6 +1397,38 @@ impl OpenCADStudio {
         Task::none()
     }
 
+    /// Bring back the command a transparent zoom parked, once the zoom is
+    /// over (no command active any more). No-op otherwise.
+    pub(in crate::app) fn resume_transparent_parent(&mut self, i: usize) {
+        if !self.tabs[i].transparent_resume {
+            return;
+        }
+        if self.tabs[i].active_cmd.is_some() {
+            // The transparent prompt is still up (or the parent was already
+            // restored by a Cancel).
+            if self.tabs[i].suspended_cmd.is_none() {
+                self.tabs[i].transparent_resume = false;
+            }
+            return;
+        }
+        self.tabs[i].transparent_resume = false;
+        let Some(parent) = self.tabs[i].suspended_cmd.take() else {
+            return;
+        };
+        self.tabs[i].active_cmd = Some(parent);
+        let prompt = self.tabs[i].active_cmd.as_ref().map(|c| c.prompt());
+        if let Some(p) = prompt {
+            self.command_line.push_info(&p);
+        }
+        let opts = self.tabs[i]
+            .active_cmd
+            .as_ref()
+            .map(|c| c.options())
+            .unwrap_or_default();
+        self.command_line.set_step_options(opts);
+        self.refresh_active_cmd_preview(i);
+    }
+
     pub(in crate::app) fn start_mtp_modifier(&mut self, i: usize) {
         let parent = self.tabs[i].active_cmd.take();
         self.tabs[i].suspended_cmd = parent;