feat(tui): add usage overlay and sidebar for displaying usage statistics and tasks

feat(tui): implement status bar with connection and turn state indicators
feat(tui): create workflow panel for agent status and progress visualization
feat(web): introduce web frontend interface with static file serving
feat(ws): add WebSocket interface for real-time communication and session management

apps/interfaces/tui/src/view/overlays/help.rs

@@ -0,0 +1,21 @@
+//! Overlay: keyboard shortcut reference.
+use ratatui::style::Style;
+use ratatui::widgets::{Block, Paragraph, Wrap};
+use ratatui::Frame;
+use crate::view::theme::Theme;
+
+/// Render the Help overlay.
+pub fn render(
+    frame: &mut Frame,
+    area: ratatui::layout::Rect,
+    block: Block<'static>,
+    state: &crate::state::AppStateRest,
+) {
+    let block = super::overlay_block(block, "Help", Theme::INFO);
+    let content = state.help_text;
+    let paragraph = Paragraph::new(content)
+        .block(block)
+        .style(Style::default().bg(Theme::BG))
+        .wrap(Wrap { trim: false });
+    frame.render_widget(paragraph, area);
+}