Maybe Runtime subsystem done

src/builtin/tasktree/mod.rs

@@ -0,0 +1,83 @@
+use crate::runtime::{Command, EventResult, PanelProvider, Source};
+use crossterm::event::Event;
+use ratatui::{
+    buffer::Buffer,
+    layout::{Constraint, Direction, Layout, Rect},
+    style::{Color, Style},
+    text::{Line, Span},
+    widgets::{Paragraph, Widget, Wrap},
+};
+
+pub struct TaskTreeProvider;
+
+impl TaskTreeProvider {
+    pub fn new() -> Self { Self }
+}
+
+impl PanelProvider for TaskTreeProvider {
+    fn as_any(&self) -> &dyn std::any::Any { self }
+    fn as_any_mut(&mut self) -> &mut dyn std::any::Any { self }
+
+    fn id(&self) -> &str { "tasktree" }
+
+    fn render(&mut self, area: Rect, buf: &mut Buffer) {
+        let vertical = Layout::default()
+            .direction(Direction::Vertical)
+            .constraints([Constraint::Length(1), Constraint::Min(0)])
+            .split(area);
+
+        let tabs = Paragraph::new("[Tree]  [Chain]  [By Agent]")
+            .style(Style::default().fg(Color::DarkGray));
+        tabs.render(vertical[0], buf);
+
+        let content = Paragraph::new(vec![
+            Line::from(""),
+            agent_line("👤", "Secretary", Color::Cyan, "idle", Color::Green),
+            task_line(" └─", "✅", Color::Green, "Explain API to user"),
+            Line::from(""),
+            agent_line("🧭", "Driver", Color::Yellow, "work", Color::Yellow),
+            task_line(" ├─", "🟡", Color::Yellow, "Research async patterns"),
+            task_line(" └─", "⚪", Color::DarkGray, "Check error handling"),
+            Line::from(""),
+            agent_line("🛡️", "NegFeedback", Color::Red, "idle", Color::Green),
+            task_line(" └─", "✅", Color::Green, "Flag race condition"),
+            Line::from(""),
+            agent_line("⚡", "Executor", Color::Magenta, "work", Color::Yellow),
+            task_line(" └─", "🟡", Color::Yellow, "cargo test..."),
+            Line::from(""),
+            Line::from("3 idle | 2 work").style(Style::default().fg(Color::DarkGray)),
+        ])
+        .wrap(Wrap { trim: true });
+
+        content.render(vertical[1], buf);
+    }
+
+    fn handle_event(&mut self, _event: Event) -> (EventResult, Vec<Command>) {
+        (EventResult::PassThrough, Vec::new())
+    }
+
+    fn focus_changed(&mut self, _focused: bool) {}
+    fn hide(&mut self) {}
+    fn show(&mut self) {}
+    fn shutdown(&mut self) {}
+
+    fn can_open(&self, _source: &Source, _mime_hint: Option<&str>) -> i32 { 0 }
+}
+
+fn agent_line<'a>(icon: &'a str, name: &'a str, name_color: Color, status: &'a str, status_color: Color) -> Line<'a> {
+    Line::from(vec![
+        Span::raw(icon),
+        Span::raw(" "),
+        Span::styled(name, Style::default().fg(name_color).add_modifier(ratatui::style::Modifier::BOLD)),
+        Span::raw(" "),
+        Span::styled(format!("● {}", status), Style::default().fg(status_color)),
+    ])
+}
+
+fn task_line<'a>(indent: &'a str, icon: &'a str, icon_color: Color, text: &'a str) -> Line<'a> {
+    Line::from(vec![
+        Span::styled(indent, Style::default().fg(Color::DarkGray)),
+        Span::styled(format!("{} ", icon), Style::default().fg(icon_color)),
+        Span::raw(text),
+    ])
+}