feat(tui): tambah dan pasang sidebar dashboard permanen

Sidebar kanan permanen (Workflow/Tasks/Usage) menggantikan panel todo
ad-hoc yang lama. Widget baca state yang sudah ada, tidak ada perubahan
skema AppStateRest.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/view/workflow.rs

@@ -14,7 +14,7 @@ use ratatui::text::{Line, Span};
 use ratatui::widgets::{Block, Borders, Paragraph, Wrap};
 use ratatui::Frame;
 use super::theme::Theme;
-use crate::app::workflow::engine::AgentState;
+use crate::app::workflow::engine::{AgentState, WorkflowAgent};
 
 /// Icons for agent states.
 fn state_icon(state: AgentState) -> &'static str {
@@ -208,4 +208,49 @@ fn build_session_lines(state: &crate::app::state::rest::AppStateRest) -> Vec<Lin
     lines
 }
 
+/// Render the compact Workflow widget for the persistent sidebar: one
+/// line per agent (icon + name), truncated to whatever fits with a
+/// trailing "+N more" hint pointing at `/workflow` for the full view.
+///
+/// Flow: bordered `Block` titled "Workflow" → empty state if no agents →
+/// else `split_for_display` caps the list to the inner height (minus one
+/// row for the hint line, if needed) → one line per visible agent.
+pub fn draw_workflow_widget(frame: &mut Frame, area: Rect, state: &crate::app::state::rest::AppStateRest) {
+    let block = Block::default()
+        .title(Span::styled(" Workflow ", Style::default().fg(Theme::PRIMARY).add_modifier(Modifier::BOLD)))
+        .borders(Borders::ALL)
+        .border_style(Style::default().fg(Theme::BORDER));
+    let budget = (block.inner(area).height as usize).max(1);
+
+    let agents = &state.workflow_engine.agents;
+    let lines: Vec<Line> = if agents.is_empty() {
+        vec![Line::from(Span::styled(
+            " No workflow running.",
+            Style::default().fg(Theme::TEXT_DIM),
+        ))]
+    } else {
+        let show_hint = agents.len() > budget;
+        let item_budget = if show_hint { budget.saturating_sub(1).max(1) } else { budget };
+        let (visible, hidden) = super::split_for_display(agents.as_slice(), item_budget);
+        let mut lines: Vec<Line> = visible.iter().map(workflow_agent_line).collect();
+        if show_hint {
+            lines.push(super::overflow_hint_line(hidden, "/workflow"));
+        }
+        lines
+    };
+
+    let paragraph = Paragraph::new(lines).block(block);
+    frame.render_widget(paragraph, area);
+}
+
+/// One compact line for a single agent: state icon + name, state-colored.
+fn workflow_agent_line(agent: &WorkflowAgent) -> Line<'static> {
+    let color = state_color(agent.status.state);
+    let icon = state_icon(agent.status.state);
+    Line::from(vec![
+        Span::styled(format!(" {icon} "), Style::default().fg(color).add_modifier(Modifier::BOLD)),
+        Span::styled(agent.name.clone(), Style::default().fg(Theme::TEXT)),
+    ])
+}
+
 use ratatui::style::Color;