Three-pane subconscious debug screen with shared widgets

New layout for F3 screen:
- Top-left: agent list using ratatui List widget with ListState
- Middle-left: expandable agent state (persistent across runs)
- Bottom-left: memory store activity by provenance, walked keys
- Right: context tree from fork point, reusing SectionTree

Tab/Shift-Tab cycles focus clockwise between panes; focused pane
gets white border. Each pane handles its own input when focused.

Extracted user/widgets.rs:
- SectionTree (moved from mod.rs): expand/collapse tree for ContextSection
- pane_block_focused(): standard bordered block with focus indicator
- format_age()/format_ts_age(): shared duration formatting

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/user/context.rs

@@ -1,120 +1,35 @@
 // context_screen.rs — F2 context/debug overlay
 //
 // Full-screen overlay showing model info, context window breakdown,
-// and runtime state. Supports tree navigation with expand/collapse.
+// and runtime state. Uses SectionTree for the expand/collapse tree.
 
 use ratatui::{
     layout::Rect,
-    style::{Color, Modifier, Style},
+    style::{Color, Style},
     text::Line,
-    widgets::{Block, Borders, Paragraph, Wrap},
+    widgets::{Paragraph, Wrap},
     Frame,
-    crossterm::event::KeyCode,
 };
 
 use super::{App, ScreenView, screen_legend};
-use crate::agent::context::ContextSection;
+use super::widgets::{SectionTree, pane_block};
 
 pub(crate) struct ConsciousScreen {
     agent: std::sync::Arc<tokio::sync::Mutex<crate::agent::Agent>>,
-    scroll: u16,
-    selected: Option<usize>,
-    expanded: std::collections::HashSet<usize>,
+    tree: SectionTree,
 }
 
 impl ConsciousScreen {
     pub fn new(agent: std::sync::Arc<tokio::sync::Mutex<crate::agent::Agent>>) -> Self {
-        Self { agent, scroll: 0, selected: None, expanded: std::collections::HashSet::new() }
+        Self { agent, tree: SectionTree::new() }
     }
 
-    fn read_context_state(&self) -> Vec<ContextSection> {
+    fn read_context_state(&self) -> Vec<crate::agent::context::ContextSection> {
         match self.agent.try_lock() {
             Ok(ag) => ag.context_state_summary(),
             Err(_) => Vec::new(),
         }
     }
-
-    fn item_count(&self, context_state: &[ContextSection]) -> usize {
-        fn count_section(section: &ContextSection, expanded: &std::collections::HashSet<usize>, idx: &mut usize) -> usize {
-            let my_idx = *idx;
-            *idx += 1;
-            let mut total = 1;
-            if expanded.contains(&my_idx) {
-                for child in &section.children {
-                    total += count_section(child, expanded, idx);
-                }
-            }
-            total
-        }
-        let mut idx = 0;
-        let mut total = 0;
-        for section in context_state {
-            total += count_section(section, &self.expanded, &mut idx);
-        }
-        total
-    }
-
-    fn scroll_to_selected(&mut self, _item_count: usize) {
-        let header_lines = 8u16;
-        if let Some(sel) = self.selected {
-            let sel_line = header_lines + sel as u16;
-            if sel_line < self.scroll + 2 {
-                self.scroll = sel_line.saturating_sub(2);
-            } else if sel_line > self.scroll + 30 {
-                self.scroll = sel_line.saturating_sub(15);
-            }
-        }
-    }
-
-    fn render_section(
-        &self,
-        section: &ContextSection,
-        depth: usize,
-        lines: &mut Vec<Line>,
-        idx: &mut usize,
-    ) {
-        let my_idx = *idx;
-        let selected = self.selected == Some(my_idx);
-        let expanded = self.expanded.contains(&my_idx);
-        let has_children = !section.children.is_empty();
-        let has_content = !section.content.is_empty();
-        let expandable = has_children || has_content;
-
-        let indent = "  ".repeat(depth + 1);
-        let marker = if !expandable { " " } else if expanded { "▼" } else { "▶" };
-        let label = format!("{}{} {:30} {:>6} tokens", indent, marker, section.name, section.tokens);
-        let style = if selected {
-            Style::default().fg(Color::Yellow).add_modifier(Modifier::BOLD)
-        } else {
-            Style::default()
-        };
-        lines.push(Line::styled(label, style));
-        *idx += 1;
-
-        if expanded {
-            if has_children {
-                for child in &section.children {
-                    self.render_section(child, depth + 1, lines, idx);
-                }
-            } else if has_content {
-                let content_indent = format!("{}    │ ", "  ".repeat(depth + 1));
-                let content_lines: Vec<&str> = section.content.lines().collect();
-                let show = content_lines.len().min(50);
-                for line in &content_lines[..show] {
-                    lines.push(Line::styled(
-                        format!("{}{}", content_indent, line),
-                        Style::default().fg(Color::DarkGray),
-                    ));
-                }
-                if content_lines.len() > 50 {
-                    lines.push(Line::styled(
-                        format!("{}... ({} more lines)", content_indent, content_lines.len() - 50),
-                        Style::default().fg(Color::DarkGray),
-                    ));
-                }
-            }
-        }
-    }
 }
 
 impl ScreenView for ConsciousScreen {
@@ -126,32 +41,7 @@ impl ScreenView for ConsciousScreen {
             if let ratatui::crossterm::event::Event::Key(key) = event {
                 if key.kind != ratatui::crossterm::event::KeyEventKind::Press { continue; }
                 let context_state = self.read_context_state();
-                let item_count = self.item_count(&context_state);
-
-                match key.code {
-                KeyCode::Up => {
-                    self.selected = Some(self.selected.unwrap_or(0).saturating_sub(1));
-                    self.scroll_to_selected(item_count);
-                }
-                KeyCode::Down => {
-                    let max = item_count.saturating_sub(1);
-                    self.selected = Some(self.selected.map_or(0, |s| (s + 1).min(max)));
-                    self.scroll_to_selected(item_count);
-                }
-                KeyCode::Right | KeyCode::Enter => {
-                    if let Some(sel) = self.selected {
-                        self.expanded.insert(sel);
-                    }
-                }
-                KeyCode::Left => {
-                    if let Some(sel) = self.selected {
-                        self.expanded.remove(&sel);
-                    }
-                }
-                KeyCode::PageUp => { self.scroll = self.scroll.saturating_sub(20); }
-                KeyCode::PageDown => { self.scroll += 20; }
-                _ => {}
-            }
+                self.tree.handle_nav(key.code, &context_state);
             }
         }
 
@@ -185,10 +75,7 @@ impl ScreenView for ConsciousScreen {
             ));
             lines.push(Line::raw(""));
 
-            let mut flat_idx = 0usize;
-            for section in &context_state {
-                self.render_section(section, 0, &mut lines, &mut flat_idx);
-            }
+            self.tree.render_sections(&context_state, &mut lines);
 
             lines.push(Line::raw(format!("  {:23} {:>6} tokens", "────────", "──────")));
             lines.push(Line::raw(format!("  {:23} {:>6} tokens", "Total", total)));
@@ -207,16 +94,13 @@ impl ScreenView for ConsciousScreen {
         lines.push(Line::raw(format!("  Running processes: {}", app.running_processes)));
         lines.push(Line::raw(format!("  Active tools: {}", app.active_tools.lock().unwrap().len())));
 
-        let block = Block::default()
-            .title_top(Line::from(screen_legend()).left_aligned())
-            .title_top(Line::from(" context ").right_aligned())
-            .borders(Borders::ALL)
-            .border_style(Style::default().fg(Color::Cyan));
+        let block = pane_block("context")
+            .title_top(Line::from(screen_legend()).left_aligned());
 
         let para = Paragraph::new(lines)
             .block(block)
             .wrap(Wrap { trim: false })
-            .scroll((self.scroll, 0));
+            .scroll((self.tree.scroll, 0));
 
         frame.render_widget(para, area);
     }

src/user/mod.rs

@@ -8,6 +8,7 @@ mod context;
 mod subconscious;
 mod unconscious;
 mod thalamus;
+mod widgets;
 
 use anyhow::Result;
 use std::io::Write;

src/user/subconscious.rs

@@ -1,27 +1,52 @@
 // subconscious_screen.rs — F3 subconscious agent overlay
+//
+// Three-pane layout:
+//   Top-left:     Agent list (↑/↓ select)
+//   Bottom-left:  Detail — outputs from selected agent's last run
+//   Right:        Context tree from fork point (→/Enter expand, ← collapse)
 
 use ratatui::{
-    layout::Rect,
+    layout::{Constraint, Layout, Rect},
     style::{Color, Modifier, Style},
     text::{Line, Span},
-    widgets::{Block, Borders, Paragraph, Wrap},
+    widgets::{List, ListItem, ListState, Paragraph, Wrap},
     Frame,
     crossterm::event::KeyCode,
 };
 
 use super::{App, ScreenView, screen_legend};
-use crate::agent::context::ConversationEntry;
-use crate::agent::api::Role;
+use super::widgets::{SectionTree, pane_block_focused, format_age, format_ts_age};
+use crate::agent::context::ContextSection;
+
+#[derive(Clone, Copy, PartialEq)]
+enum Pane { Agents, Outputs, History, Context }
+
+// Clockwise: top-left → right → bottom-left → middle-left
+const PANE_ORDER: &[Pane] = &[Pane::Agents, Pane::Context, Pane::History, Pane::Outputs];
 
 pub(crate) struct SubconsciousScreen {
-    selected: usize,
-    detail: bool,
-    scroll: u16,
+    focus: Pane,
+    list_state: ListState,
+    output_tree: SectionTree,
+    context_tree: SectionTree,
+    history_scroll: u16,
 }
 
 impl SubconsciousScreen {
     pub fn new() -> Self {
-        Self { selected: 0, detail: false, scroll: 0 }
+        let mut list_state = ListState::default();
+        list_state.select(Some(0));
+        Self {
+            focus: Pane::Agents,
+            list_state,
+            output_tree: SectionTree::new(),
+            context_tree: SectionTree::new(),
+            history_scroll: 0,
+        }
+    }
+
+    fn selected(&self) -> usize {
+        self.list_state.selected().unwrap_or(0)
     }
 }
 
@@ -30,206 +55,232 @@ impl ScreenView for SubconsciousScreen {
 
     fn tick(&mut self, frame: &mut Frame, area: Rect,
             events: &[ratatui::crossterm::event::Event], app: &mut App) {
+        let context_sections = self.read_sections(app);
+        let output_sections = self.output_sections(app);
+
         for event in events {
             if let ratatui::crossterm::event::Event::Key(key) = event {
                 if key.kind != ratatui::crossterm::event::KeyEventKind::Press { continue; }
                 match key.code {
-                    KeyCode::Up if !self.detail => {
-                        self.selected = self.selected.saturating_sub(1);
+                    KeyCode::Tab => {
+                        let idx = PANE_ORDER.iter().position(|p| *p == self.focus).unwrap_or(0);
+                        self.focus = PANE_ORDER[(idx + 1) % PANE_ORDER.len()];
                     }
-                    KeyCode::Down if !self.detail => {
-                        self.selected = (self.selected + 1)
-                            .min(app.agent_state.len().saturating_sub(1));
+                    KeyCode::BackTab => {
+                        let idx = PANE_ORDER.iter().position(|p| *p == self.focus).unwrap_or(0);
+                        self.focus = PANE_ORDER[(idx + PANE_ORDER.len() - 1) % PANE_ORDER.len()];
                     }
-                    KeyCode::Enter | KeyCode::Right if !self.detail => {
-                        self.detail = true;
-                        self.scroll = 0;
+                    code => match self.focus {
+                        Pane::Agents => match code {
+                            KeyCode::Up => {
+                                self.list_state.select_previous();
+                                self.reset_pane_state();
+                            }
+                            KeyCode::Down => {
+                                self.list_state.select_next();
+                                self.reset_pane_state();
+                            }
+                            _ => {}
+                        }
+                        Pane::Outputs => self.output_tree.handle_nav(code, &output_sections),
+                        Pane::History => match code {
+                            KeyCode::Up => self.history_scroll = self.history_scroll.saturating_sub(3),
+                            KeyCode::Down => self.history_scroll += 3,
+                            KeyCode::PageUp => self.history_scroll = self.history_scroll.saturating_sub(20),
+                            KeyCode::PageDown => self.history_scroll += 20,
+                            _ => {}
+                        }
+                        Pane::Context => self.context_tree.handle_nav(code, &context_sections),
                     }
-                    KeyCode::Esc | KeyCode::Left if self.detail => {
-                        self.detail = false;
-                    }
-                    KeyCode::Up if self.detail => {
-                        self.scroll = self.scroll.saturating_sub(3);
-                    }
-                    KeyCode::Down if self.detail => {
-                        self.scroll += 3;
-                    }
-                    KeyCode::PageUp => { self.scroll = self.scroll.saturating_sub(20); }
-                    KeyCode::PageDown => { self.scroll += 20; }
-                    _ => {}
                 }
             }
         }
 
-        if self.detail {
-            self.draw_detail(frame, area, app);
-        } else {
-            self.draw_list(frame, area, app);
-        }
+        // Layout: left column (38%) | right column (62%)
+        let [left, right] = Layout::horizontal([
+            Constraint::Percentage(38),
+            Constraint::Percentage(62),
+        ]).areas(area);
+
+        // Left column: agent list (top) | outputs (middle) | history (bottom, main)
+        let agent_count = app.agent_state.len().max(1) as u16;
+        let list_height = (agent_count + 2).min(left.height / 4);
+        let output_lines = app.agent_state.get(self.selected())
+            .map(|s| s.state.values().map(|v| v.lines().count() + 1).sum::<usize>())
+            .unwrap_or(0);
+        let output_height = (output_lines as u16 + 2).min(left.height / 4).max(3);
+        let [list_area, output_area, history_area] = Layout::vertical([
+            Constraint::Length(list_height),
+            Constraint::Length(output_height),
+            Constraint::Min(5),
+        ]).areas(left);
+
+        self.draw_list(frame, list_area, app);
+        self.draw_outputs(frame, output_area, app);
+        self.draw_history(frame, history_area, app);
+        self.draw_context(frame, right, &context_sections, app);
     }
 }
 
 impl SubconsciousScreen {
-    fn draw_list(&self, frame: &mut Frame, area: Rect, app: &App) {
-        let mut lines: Vec<Line> = Vec::new();
-        let section = Style::default().fg(Color::Yellow);
-        let hint = Style::default().fg(Color::DarkGray).add_modifier(Modifier::ITALIC);
+    fn reset_pane_state(&mut self) {
+        self.output_tree = SectionTree::new();
+        self.context_tree = SectionTree::new();
+        self.history_scroll = 0;
+    }
 
-        lines.push(Line::raw(""));
-        let walked = app.walked_count;
-        lines.push(Line::styled(
-            format!("── Subconscious Agents ──  walked: {}", walked), section));
-        lines.push(Line::styled("  (↑/↓ select, Enter view log)", hint));
-        lines.push(Line::raw(""));
+    fn output_sections(&self, app: &App) -> Vec<ContextSection> {
+        let snap = match app.agent_state.get(self.selected()) {
+            Some(s) => s,
+            None => return Vec::new(),
+        };
+        snap.state.iter().map(|(key, val)| {
+            ContextSection {
+                name: key.clone(),
+                tokens: 0,
+                content: val.clone(),
+                children: Vec::new(),
+            }
+        }).collect()
+    }
 
-        if app.agent_state.is_empty() {
-            lines.push(Line::styled("  (no agents loaded)", hint));
-        }
+    fn read_sections(&self, app: &App) -> Vec<ContextSection> {
+        let snap = match app.agent_state.get(self.selected()) {
+            Some(s) => s,
+            None => return Vec::new(),
+        };
+        snap.forked_agent.as_ref()
+            .and_then(|agent| agent.try_lock().ok())
+            .map(|ag| ag.conversation_sections_from(snap.fork_point))
+            .unwrap_or_default()
+    }
 
-        for (i, snap) in app.agent_state.iter().enumerate() {
-            let selected = i == self.selected;
-            let prefix = if selected { "▸ " } else { "  " };
-            let bg = if selected {
-                Style::default().bg(Color::DarkGray)
-            } else {
-                Style::default()
-            };
-
-            let status_spans = if snap.running {
-                vec![
+    fn draw_list(&mut self, frame: &mut Frame, area: Rect, app: &App) {
+        let items: Vec<ListItem> = app.agent_state.iter().map(|snap| {
+            if snap.running {
+                ListItem::from(Line::from(vec![
+                    Span::styled(&snap.name, Style::default().fg(Color::Green)),
+                    Span::styled(" ● ", Style::default().fg(Color::Green)),
                     Span::styled(
-                        format!("{}{:<30}", prefix, snap.name),
-                        bg.fg(Color::Green),
+                        format!("p:{} t:{}", snap.current_phase, snap.turn),
+                        Style::default().fg(Color::DarkGray),
                     ),
-                    Span::styled("●  ", bg.fg(Color::Green)),
-                    Span::styled(
-                        format!("phase: {}  turn: {}", snap.current_phase, snap.turn),
-                        bg,
-                    ),
-                ]
+                ]))
             } else {
                 let ago = snap.last_run_secs_ago
-                    .map(|s| {
-                        if s < 60.0 { format!("{:.0}s ago", s) }
-                        else if s < 3600.0 { format!("{:.0}m ago", s / 60.0) }
-                        else { format!("{:.1}h ago", s / 3600.0) }
-                    })
-                    .unwrap_or_else(|| "never".to_string());
+                    .map(|s| format_age(s))
+                    .unwrap_or_else(|| "—".to_string());
                 let entries = snap.forked_agent.as_ref()
                     .and_then(|a| a.try_lock().ok())
                     .map(|ag| ag.context.entries.len().saturating_sub(snap.fork_point))
                     .unwrap_or(0);
-                vec![
+                ListItem::from(Line::from(vec![
+                    Span::styled(&snap.name, Style::default().fg(Color::Gray)),
+                    Span::styled(" ○ ", Style::default().fg(Color::DarkGray)),
                     Span::styled(
-                        format!("{}{:<30}", prefix, snap.name),
-                        bg.fg(Color::Gray),
+                        format!("{} {}e", ago, entries),
+                        Style::default().fg(Color::DarkGray),
                     ),
-                    Span::styled("○  ", bg.fg(Color::DarkGray)),
-                    Span::styled(
-                        format!("idle  last: {}  entries: {}",
-                            ago, entries),
-                        bg.fg(Color::DarkGray),
-                    ),
-                ]
-            };
-            lines.push(Line::from(status_spans));
+                ]))
+            }
+        }).collect();
+
+        let list = List::new(items)
+            .block(pane_block_focused("agents", self.focus == Pane::Agents)
+                .title_top(Line::from(screen_legend()).left_aligned()))
+            .highlight_symbol("▸ ")
+            .highlight_style(Style::default().bg(Color::DarkGray));
+
+        frame.render_stateful_widget(list, area, &mut self.list_state);
+    }
+
+    fn draw_outputs(&self, frame: &mut Frame, area: Rect, app: &App) {
+        let sections = self.output_sections(app);
+        let mut lines: Vec<Line> = Vec::new();
+
+        if sections.is_empty() {
+            let dim = Style::default().fg(Color::DarkGray);
+            let snap = app.agent_state.get(self.selected());
+            let msg = if snap.is_some_and(|s| s.running) { "(running...)" } else { "—" };
+            lines.push(Line::styled(format!("  {}", msg), dim));
+        } else {
+            self.output_tree.render_sections(&sections, &mut lines);
         }
 
-        let block = Block::default()
-            .title_top(Line::from(screen_legend()).left_aligned())
-            .title_top(Line::from(" subconscious ").right_aligned())
-            .borders(Borders::ALL)
-            .border_style(Style::default().fg(Color::Cyan));
-
         let para = Paragraph::new(lines)
-            .block(block)
+            .block(pane_block_focused("state", self.focus == Pane::Outputs))
             .wrap(Wrap { trim: false })
-            .scroll((self.scroll, 0));
+            .scroll((self.output_tree.scroll, 0));
         frame.render_widget(para, area);
     }
 
-    fn draw_detail(&self, frame: &mut Frame, area: Rect, app: &App) {
-        let snap = match app.agent_state.get(self.selected) {
-            Some(s) => s,
-            None => return,
-        };
+    fn draw_history(&self, frame: &mut Frame, area: Rect, app: &App) {
+        let dim = Style::default().fg(Color::DarkGray);
+        let key_style = Style::default().fg(Color::Yellow);
 
         let mut lines: Vec<Line> = Vec::new();
-        let section = Style::default().fg(Color::Yellow);
-        let hint = Style::default().fg(Color::DarkGray).add_modifier(Modifier::ITALIC);
+        let mut title = "memory store activity".to_string();
 
-        lines.push(Line::raw(""));
-        lines.push(Line::styled(format!("── {} ──", snap.name), section));
-        lines.push(Line::styled("  (Esc/← back, ↑/↓/PgUp/PgDn scroll)", hint));
-        lines.push(Line::raw(""));
+        if let Some(snap) = app.agent_state.get(self.selected()) {
+            let short_name = snap.name.strip_prefix("subconscious-").unwrap_or(&snap.name);
+            title = format!("{} store activity", short_name);
 
-        // Read entries from the forked agent (from fork point onward)
-        let entries: Vec<ConversationEntry> = snap.forked_agent.as_ref()
-            .and_then(|agent| agent.try_lock().ok())
-            .map(|ag| ag.context.entries.get(snap.fork_point..).unwrap_or(&[]).to_vec())
-            .unwrap_or_default();
-
-        if entries.is_empty() {
-            lines.push(Line::styled("  (no run data)", hint));
-        }
-
-        for entry in &entries {
-            if entry.is_log() {
-                if let ConversationEntry::Log(text) = entry {
-                    lines.push(Line::styled(
-                        format!("  [log] {}", text),
-                        Style::default().fg(Color::DarkGray),
-                    ));
+            if snap.history.is_empty() {
+                lines.push(Line::styled("  (no store activity)", dim));
+            } else {
+                for (key, ts) in &snap.history {
+                    lines.push(Line::from(vec![
+                        Span::styled(format!("  {:>6} ", format_ts_age(*ts)), dim),
+                        Span::styled(key.as_str(), key_style),
+                    ]));
                 }
-                continue;
             }
 
-            let msg = entry.message();
-            let (role_str, role_color) = match msg.role {
-                Role::User => ("user", Color::Cyan),
-                Role::Assistant => ("assistant", Color::Reset),
-                Role::Tool => ("tool", Color::DarkGray),
-                Role::System => ("system", Color::Yellow),
-            };
-
-            let text = msg.content_text();
-            let tool_info = msg.tool_calls.as_ref().map(|tc| {
-                tc.iter().map(|c| c.function.name.as_str())
-                    .collect::<Vec<_>>().join(", ")
-            });
-
-            let header = match &tool_info {
-                Some(tools) => format!("  [{} → {}]", role_str, tools),
-                None => format!("  [{}]", role_str),
-            };
-            lines.push(Line::styled(header, Style::default().fg(role_color)));
-
-            if !text.is_empty() {
-                for line in text.lines().take(20) {
-                    lines.push(Line::styled(
-                        format!("    {}", line),
-                        Style::default().fg(Color::Gray),
-                    ));
-                }
-                if text.lines().count() > 20 {
-                    lines.push(Line::styled(
-                        format!("    ... ({} more lines)", text.lines().count() - 20),
-                        hint,
-                    ));
+            if !snap.walked.is_empty() {
+                lines.push(Line::raw(""));
+                lines.push(Line::styled(
+                    format!("  walked ({}):", snap.walked.len()),
+                    Style::default().fg(Color::Cyan),
+                ));
+                for key in &snap.walked {
+                    lines.push(Line::styled(format!("    {}", key), dim));
                 }
             }
         }
 
-        let block = Block::default()
-            .title_top(Line::from(screen_legend()).left_aligned())
-            .title_top(Line::from(format!(" {} ", snap.name)).right_aligned())
-            .borders(Borders::ALL)
-            .border_style(Style::default().fg(Color::Cyan));
-
         let para = Paragraph::new(lines)
-            .block(block)
+            .block(pane_block_focused(&title, self.focus == Pane::History))
             .wrap(Wrap { trim: false })
-            .scroll((self.scroll, 0));
+            .scroll((self.history_scroll, 0));
+        frame.render_widget(para, area);
+    }
+
+    fn draw_context(
+        &self,
+        frame: &mut Frame,
+        area: Rect,
+        sections: &[ContextSection],
+        app: &App,
+    ) {
+        let mut lines: Vec<Line> = Vec::new();
+
+        if sections.is_empty() {
+            lines.push(Line::styled(
+                "  (no conversation data)",
+                Style::default().fg(Color::DarkGray).add_modifier(Modifier::ITALIC),
+            ));
+        } else {
+            self.context_tree.render_sections(sections, &mut lines);
+        }
+
+        let title = app.agent_state.get(self.selected())
+            .map(|s| s.name.as_str())
+            .unwrap_or("—");
+
+        let para = Paragraph::new(lines)
+            .block(pane_block_focused(title, self.focus == Pane::Context))
+            .wrap(Wrap { trim: false })
+            .scroll((self.context_tree.scroll, 0));
         frame.render_widget(para, area);
     }
 }

src/user/widgets.rs

@@ -0,0 +1,175 @@
+// widgets.rs — Shared TUI helpers and reusable components
+
+use ratatui::{
+    style::{Color, Modifier, Style},
+    text::Line,
+    widgets::{Block, Borders},
+    crossterm::event::KeyCode,
+};
+use crate::agent::context::ContextSection;
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+/// Standard pane block — cyan border, right-aligned title.
+pub fn pane_block(title: &str) -> Block<'_> {
+    Block::default()
+        .title_top(Line::from(format!(" {} ", title)).right_aligned())
+        .borders(Borders::ALL)
+        .border_style(Style::default().fg(Color::Cyan))
+}
+
+/// Focused pane block — brighter border to indicate focus.
+pub fn pane_block_focused(title: &str, focused: bool) -> Block<'_> {
+    let color = if focused { Color::White } else { Color::Cyan };
+    Block::default()
+        .title_top(Line::from(format!(" {} ", title)).right_aligned())
+        .borders(Borders::ALL)
+        .border_style(Style::default().fg(color))
+}
+
+/// Format a duration in seconds as a compact human-readable string.
+pub fn format_age(secs: f64) -> String {
+    if secs < 60.0 { format!("{:.0}s", secs) }
+    else if secs < 3600.0 { format!("{:.0}m", secs / 60.0) }
+    else if secs < 86400.0 { format!("{:.1}h", secs / 3600.0) }
+    else { format!("{:.0}d", secs / 86400.0) }
+}
+
+/// Format a unix epoch timestamp as age from now.
+pub fn format_ts_age(ts: i64) -> String {
+    let now = std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs() as i64;
+    format_age((now - ts).max(0) as f64)
+}
+
+// ---------------------------------------------------------------------------
+// SectionTree — expand/collapse tree renderer for ContextSection
+// ---------------------------------------------------------------------------
+
+pub struct SectionTree {
+    pub selected: Option<usize>,
+    pub expanded: std::collections::HashSet<usize>,
+    pub scroll: u16,
+}
+
+impl SectionTree {
+    pub fn new() -> Self {
+        Self { selected: None, expanded: std::collections::HashSet::new(), scroll: 0 }
+    }
+
+    pub fn item_count(&self, sections: &[ContextSection]) -> usize {
+        fn count(section: &ContextSection, expanded: &std::collections::HashSet<usize>, idx: &mut usize) -> usize {
+            let my_idx = *idx;
+            *idx += 1;
+            let mut total = 1;
+            if expanded.contains(&my_idx) {
+                for child in &section.children {
+                    total += count(child, expanded, idx);
+                }
+            }
+            total
+        }
+        let mut idx = 0;
+        sections.iter().map(|s| count(s, &self.expanded, &mut idx)).sum()
+    }
+
+    pub fn handle_nav(&mut self, code: KeyCode, sections: &[ContextSection]) {
+        let item_count = self.item_count(sections);
+        match code {
+            KeyCode::Up => {
+                self.selected = Some(self.selected.unwrap_or(0).saturating_sub(1));
+                self.scroll_to_selected();
+            }
+            KeyCode::Down => {
+                let max = item_count.saturating_sub(1);
+                self.selected = Some(self.selected.map_or(0, |s| (s + 1).min(max)));
+                self.scroll_to_selected();
+            }
+            KeyCode::Right | KeyCode::Enter => {
+                if let Some(sel) = self.selected {
+                    self.expanded.insert(sel);
+                }
+            }
+            KeyCode::Left => {
+                if let Some(sel) = self.selected {
+                    self.expanded.remove(&sel);
+                }
+            }
+            KeyCode::PageUp => { self.scroll = self.scroll.saturating_sub(20); }
+            KeyCode::PageDown => { self.scroll += 20; }
+            _ => {}
+        }
+    }
+
+    fn scroll_to_selected(&mut self) {
+        if let Some(sel) = self.selected {
+            let sel_line = sel as u16;
+            if sel_line < self.scroll + 2 {
+                self.scroll = sel_line.saturating_sub(2);
+            } else if sel_line > self.scroll + 30 {
+                self.scroll = sel_line.saturating_sub(15);
+            }
+        }
+    }
+
+    pub fn render_sections(&self, sections: &[ContextSection], lines: &mut Vec<Line>) {
+        let mut idx = 0;
+        for section in sections {
+            self.render_one(section, 0, lines, &mut idx);
+        }
+    }
+
+    fn render_one(
+        &self,
+        section: &ContextSection,
+        depth: usize,
+        lines: &mut Vec<Line>,
+        idx: &mut usize,
+    ) {
+        let my_idx = *idx;
+        let selected = self.selected == Some(my_idx);
+        let expanded = self.expanded.contains(&my_idx);
+        let has_children = !section.children.is_empty();
+        let has_content = !section.content.is_empty();
+        let expandable = has_children || has_content;
+
+        let indent = "  ".repeat(depth + 1);
+        let marker = if !expandable { " " } else if expanded { "▼" } else { "▶" };
+        let label = format!("{}{} {:30} {:>6} tokens", indent, marker, section.name, section.tokens);
+        let style = if selected {
+            Style::default().fg(Color::Yellow).add_modifier(Modifier::BOLD)
+        } else {
+            Style::default()
+        };
+        lines.push(Line::styled(label, style));
+        *idx += 1;
+
+        if expanded {
+            if has_children {
+                for child in &section.children {
+                    self.render_one(child, depth + 1, lines, idx);
+                }
+            } else if has_content {
+                let content_indent = format!("{}    │ ", "  ".repeat(depth + 1));
+                let content_lines: Vec<&str> = section.content.lines().collect();
+                let show = content_lines.len().min(50);
+                for line in &content_lines[..show] {
+                    lines.push(Line::styled(
+                        format!("{}{}", content_indent, line),
+                        Style::default().fg(Color::DarkGray),
+                    ));
+                }
+                if content_lines.len() > 50 {
+                    lines.push(Line::styled(
+                        format!("{}... ({} more lines)", content_indent, content_lines.len() - 50),
+                        Style::default().fg(Color::DarkGray),
+                    ));
+                }
+            }
+        }
+    }
+}