feat(command-line): resize history panel

Refs #456

src/app/update/file.rs

@@ -274,6 +274,7 @@ impl OpenCADStudio {
             },
             plugin_repos: self.plugin_repos.clone(),
             literal_spaces: self.command_line.literal_spaces,
+            command_history_height: self.command_line.history_height,
             osmode: crate::app::settings::osmode_from_snaps(
                 self.snapper.enabled.iter(),
                 self.snapper.snap_enabled,
@@ -304,6 +305,14 @@ impl OpenCADStudio {
         self.disabled_plugins = s.disabled_plugins.iter().cloned().collect();
         self.plugin_repos = s.plugin_repos.clone();
         self.command_line.literal_spaces = s.literal_spaces;
+        self.command_line.history_height = if s.command_history_height.is_finite() {
+            s.command_history_height.clamp(
+                crate::ui::command_line::HISTORY_HEIGHT_MIN,
+                crate::ui::command_line::HISTORY_HEIGHT_MAX,
+            )
+        } else {
+            crate::ui::command_line::HISTORY_HEIGHT_DEFAULT
+        };
         let (modes, snap_enabled) = crate::app::settings::snaps_from_osmode(s.osmode);
         self.snapper.enabled = modes.into_iter().collect();
         self.snapper.snap_enabled = snap_enabled;
@@ -587,7 +596,11 @@ impl OpenCADStudio {
 
     /// Back-compat name for the many "a preference changed, persist it" sites.
     pub(in crate::app) fn persist_settings_if_changed(&mut self) {
-        self.save_config();
+        // Keep resize feedback live without writing settings on every pointer
+        // move. The release message saves the final height once.
+        if !self.command_history_resizing {
+            self.save_config();
+        }
     }
 
     /// Record that the one-time default-association prompt has been answered and

src/app/update/mod.rs

@@ -111,10 +111,10 @@ impl OpenCADStudio {
         if self.history_content.text() == latest {
             return;
         }
-        use iced::widget::text_editor::{Action, Motion};
         self.history_content = iced::widget::text_editor::Content::with_text(&latest);
-        self.history_content
-            .perform(Action::Move(Motion::DocumentEnd));
+        // The outer scrollable is anchored to the newest lines. Leaving the
+        // editor cursor at its initial position also keeps horizontal scroll at
+        // zero, so the first glyph of each line cannot be clipped.
     }
 
     /// Close the active in-canvas modal (Plan B), mirroring what closing the
@@ -1565,10 +1565,56 @@ impl OpenCADStudio {
 
             Message::CommandHistoryToggle => {
                 self.command_line.toggle_history();
+                if !self.command_line.history_open {
+                    self.command_history_resizing = false;
+                    self.command_history_drag_last = None;
+                }
                 self.sync_open_command_history();
                 Task::none()
             }
 
+            Message::CommandHistoryResizeGrab => {
+                if self.command_line.history_open {
+                    self.command_history_resizing = true;
+                    self.command_history_drag_last = None;
+                }
+                Task::none()
+            }
+
+            Message::CommandHistoryResizeMove(point) => {
+                if self.command_history_resizing {
+                    if let Some(last) = self.command_history_drag_last {
+                        let dy = point.y - last.y;
+                        let max_height =
+                            crate::ui::command_line::history_max_height(self.win_size.1);
+                        self.command_line.history_height = (self.command_line.history_height - dy)
+                            .clamp(
+                                crate::ui::command_line::HISTORY_HEIGHT_MIN,
+                                max_height,
+                            );
+                    }
+                    self.command_history_drag_last = Some(point);
+                }
+                Task::none()
+            }
+
+            Message::CommandHistoryResizeRelease => {
+                let changed = self.command_history_resizing;
+                self.command_history_resizing = false;
+                self.command_history_drag_last = None;
+                if changed {
+                    self.save_config();
+                }
+                Task::none()
+            }
+
+            Message::CommandHistoryHeightReset => {
+                self.command_line.history_height =
+                    crate::ui::command_line::HISTORY_HEIGHT_DEFAULT;
+                self.save_config();
+                Task::none()
+            }
+
             Message::CommandHistoryCopy => {
                 let text = self.command_line.history_plain_text();
                 if text.is_empty() {
@@ -1599,12 +1645,24 @@ impl OpenCADStudio {
             }
 
             Message::CommandHistoryEdit(action) => {
-                // Read-only: drop edits, keep selection / cursor / scroll so
-                // the user can still highlight and Ctrl+C the log.
-                if !action.is_edit() {
-                    self.history_content.perform(action);
+                // Read-only: drop edits, keep selection/cursor actions, and
+                // route wheel input to the outer scrollbar. The text editor
+                // remains one selectable buffer while the scrollbar stays
+                // visible and draggable.
+                if let iced::widget::text_editor::Action::Scroll { lines } = action {
+                    iced::widget::operation::scroll_by(
+                        iced::widget::Id::new(crate::ui::command_line::HISTORY_SCROLL_ID),
+                        iced::widget::scrollable::AbsoluteOffset {
+                            x: 0.0,
+                            y: lines as f32 * 14.0,
+                        },
+                    )
+                } else {
+                    if !action.is_edit() {
+                        self.history_content.perform(action);
+                    }
+                    Task::none()
                 }
-                Task::none()
             }
 
             Message::CommandSuggestionPick(cmd) => {