feat: Implement lesson generation feature and update status display

- Added functionality to generate lessons based on code reviews, including prompts and instructions for the reviewer.
- Updated the `.gitignore` to exclude lesson documentation files.
- Removed the `/lesson` command from the help menu and command parsing.
- Enhanced the status bar to display a message when a lesson is being generated.
- Introduced a new `lesson_running` state to track lesson generation progress.
- Updated various components to handle the new lesson generation workflow, including subagent events and token usage tracking.

src/view/status.rs

@@ -93,12 +93,24 @@ pub fn draw_status_bar(frame: &mut Frame, area: Rect, state: &crate::app::state:
         Style::default().fg(Theme::TEXT_MUTED),
     ));
 
-    // Render the bar using two columns
+    let center_line = if state.misc.lesson_running {
+        Line::from(vec![
+            Span::styled(
+                " 📘 Generating Lesson... ",
+                Style::default().fg(Theme::MODE_YOLO).add_modifier(Modifier::BOLD),
+            )
+        ])
+    } else {
+        Line::from("")
+    };
+
+    // Render the bar using three columns
     let chunks = Layout::default()
         .direction(Direction::Horizontal)
         .constraints([
             Constraint::Length(25),
             Constraint::Min(10),
+            Constraint::Length(60),
         ])
         .split(area);
 
@@ -113,9 +125,15 @@ pub fn draw_status_bar(frame: &mut Frame, area: Rect, state: &crate::app::state:
     let left_para = ratatui::widgets::Paragraph::new(left_line).block(block.clone());
     frame.render_widget(left_para, chunks[0]);
 
+    // Center part
+    let center_para = ratatui::widgets::Paragraph::new(center_line)
+        .block(block.clone())
+        .alignment(ratatui::layout::Alignment::Center);
+    frame.render_widget(center_para, chunks[1]);
+
     // Right part
     let right_para = ratatui::widgets::Paragraph::new(right_line)
         .block(block)
         .alignment(ratatui::layout::Alignment::Right);
-    frame.render_widget(right_para, chunks[1]);
+    frame.render_widget(right_para, chunks[2]);
 }