fix(mtext): keep arrows in editor

Route captured arrows to the MText caret only while the hidden command input retains focus.\n\nRefs #655

src/app/mod.rs

@@ -1972,9 +1972,9 @@ pub enum Message {
     },
     /// A widget captured Up/Down; resolve it only if the command input owns
     /// keyboard focus.
-    CommandLineArrowProbe { direction: ArrowKey },
+    CommandLineArrowProbe { direction: ArrowKey, extend_selection: bool },
     /// Result of the command-input focus query for a captured Up/Down key.
-    CommandLineArrowResolved { direction: ArrowKey, focused: bool },
+    CommandLineArrowResolved { direction: ArrowKey, focused: bool, extend_selection: bool },
     /// Toggle the dropdown listing the full command-line history.
     CommandHistoryToggle,
     /// Grab/move/release the expanded history panel's top resize edge.

src/app/update/mod.rs

@@ -1559,20 +1559,37 @@ impl OpenCADStudio {
                 ))
             }
 
-            Message::CommandLineArrowProbe { direction } => {
+            Message::CommandLineArrowProbe {
+                direction,
+                extend_selection,
+            } => {
                 iced::widget::operation::is_focused(iced::widget::Id::new(
                     crate::ui::command_line::CMD_INPUT_ID,
                 ))
                 .map(move |focused| Message::CommandLineArrowResolved {
                     direction,
                     focused,
+                    extend_selection,
                 })
             }
 
-            Message::CommandLineArrowResolved { direction, focused } => {
+            Message::CommandLineArrowResolved {
+                direction,
+                focused,
+                extend_selection,
+            } => {
                 if !focused {
                     return Task::none();
                 }
+                // The editor inherits arrows captured by the focused command line.
+                if self.mtext_editor.is_some() {
+                    match direction {
+                        ArrowKey::Up => self.mtext_caret_move_vertical(1, extend_selection),
+                        ArrowKey::Down => self.mtext_caret_move_vertical(-1, extend_selection),
+                        ArrowKey::Left | ArrowKey::Right => {}
+                    }
+                    return Task::none();
+                }
                 match direction {
                     ArrowKey::Up => self.update(Message::CommandHistoryPrev),
                     ArrowKey::Down => self.update(Message::CommandHistoryNext),

src/app/view/mod.rs

@@ -2266,6 +2266,7 @@ impl OpenCADStudio {
                         {
                             return Some(Message::CommandLineArrowProbe {
                                 direction: arrow?,
+                                extend_selection: modifiers.shift(),
                             });
                         }
                         // A focused web text field needs the browser clipboard;