dap-tui: ratatui device-sync dashboard

Full rewrite of dap-sync as a Rust TUI on ratatui:
- Tokyo Night theme, gradient title rule, rounded panels
- Devices sidebar with live mount status + last-sync age
- Dashboard / Sync / Logs / Config tabs
- Live sync engine: rclone mirror, NFC-aware diff, rsync
  progress parsing, podkit + mlove (fatsort) finalize
- Abort-safe subprocess handling, persisted sync state

src/ui/mod.rs

@@ -0,0 +1,108 @@
+pub mod components;
+pub mod tabs;
+pub mod theme;
+
+use crate::app::App;
+use ratatui::Frame;
+use ratatui::layout::{Constraint, Layout, Rect};
+use ratatui::style::{Style, Stylize};
+use ratatui::widgets::{Block, Borders, Clear};
+
+use theme::{BG, DIM};
+
+pub fn truncate(s: &str, max: usize) -> String {
+    if s.chars().count() <= max {
+        s.to_string()
+    } else {
+        let mut out: String = s.chars().take(max.saturating_sub(1)).collect();
+        out.push('…');
+        out
+    }
+}
+
+pub fn draw(f: &mut Frame, app: &App) {
+    let area = f.area();
+    f.render_widget(Block::default().style(Style::default().bg(BG)), area);
+
+    let v = Layout::vertical([
+        Constraint::Length(2), // title
+        Constraint::Length(1), // gradient rule
+        Constraint::Min(0),    // body
+        Constraint::Length(1), // status
+        Constraint::Length(1), // keys
+    ]);
+    let [title, rule, body, status, keys] = v.areas(area);
+
+    components::draw_title(f, title, app);
+    components::draw_rule(f, rule, app);
+
+    let [side, main] = Layout::horizontal([Constraint::Length(34), Constraint::Min(0)]).areas(body);
+    components::draw_sidebar(f, side, app);
+    draw_main(f, main, app);
+
+    components::draw_status(f, status, app);
+    components::draw_keys(f, keys, app);
+
+    if app.show_help {
+        draw_help(f);
+    }
+}
+
+fn draw_main(f: &mut Frame, area: Rect, app: &App) {
+    let [tabbar, content] =
+        Layout::vertical([Constraint::Length(1), Constraint::Min(0)]).areas(area);
+    components::draw_tabbar(f, tabbar, app);
+    match app.tab {
+        crate::app::Tab::Dashboard => tabs::dashboard::draw(f, content, app),
+        crate::app::Tab::Sync => tabs::sync::draw(f, content, app),
+        crate::app::Tab::Logs => tabs::logs::draw(f, content, app),
+        crate::app::Tab::Config => tabs::config_view::draw(f, content, app),
+    }
+}
+
+fn draw_help(f: &mut Frame) {
+    let area = f.area();
+    let box_w = 58;
+    let box_h = 16;
+    let x = (area.width.saturating_sub(box_w)) / 2;
+    let y = (area.height.saturating_sub(box_h)) / 2;
+    let rect = Rect::new(
+        x.max(0),
+        y.max(0),
+        box_w.min(area.width),
+        box_h.min(area.height),
+    );
+    f.render_widget(Clear, rect);
+    let block = Block::default()
+        .borders(Borders::ALL)
+        .border_style(Style::default().fg(crate::ui::theme::ACCENT))
+        .style(Style::default().bg(crate::ui::theme::PANEL_BG))
+        .title("  KEYBINDINGS  ".cyan().bold());
+    let lines = [
+        "  ↑↓ / j k     move selection",
+        "  s / Enter     sync selected device",
+        "  a             abort running sync",
+        "  Tab / 1-4     switch tab",
+        "  r             refresh devices",
+        "  f             toggle log follow",
+        "  u / d         scroll logs",
+        "  x             clear logs",
+        "  ? / h         this help",
+        "  q / Esc       quit",
+        "",
+        "  ←  →          (todo: device nav)",
+    ];
+    let mut spans = Vec::new();
+    for (i, line) in lines.iter().enumerate() {
+        if i > 0 {
+            spans.push(ratatui::text::Line::raw(""));
+        }
+        let styled = if line.contains('/') {
+            ratatui::text::Span::styled(*line, ratatui::style::Style::default().fg(crate::ui::theme::FG))
+        } else {
+            ratatui::text::Span::styled(*line, ratatui::style::Style::default().fg(DIM))
+        };
+        spans.push(ratatui::text::Line::from(styled));
+    }
+    f.render_widget(ratatui::widgets::Paragraph::new(ratatui::text::Text::from(spans)).block(block), rect);
+}