feat(hh): ratatui TUI client — chat, live roster, themes

- Connect subcommand: SRP auth then a ratatui UI over tokio + crossterm.
- Async ws (tokio-tungstenite); reader task decrypts/parses frames into events.
- Panes: top bar (e2e + house N/cap), chat scrollback, roster (self marked ⛧),
  input box. Undecryptable frames surface as a system line, not a silent drop.
- Themes (vestments) via TOML --theme; default occult-monochrome + neon.
- Verified live in tmux: render, chat round-trip, roster, join/leave.
- Adds fernet python->rust interop regression test.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

hh/src/ui.rs

@@ -0,0 +1,121 @@
+//! ratatui rendering — top bar, chat, roster, input.
+
+use crate::app::{App, ChatLine};
+use crate::theme::Theme;
+use ratatui::layout::{Constraint, Layout, Position};
+use ratatui::style::{Modifier, Style};
+use ratatui::text::{Line, Span};
+use ratatui::widgets::{Block, List, ListItem, Paragraph, Wrap};
+use ratatui::Frame;
+
+pub fn draw(f: &mut Frame, app: &App, theme: &Theme) {
+    let rows = Layout::vertical([
+        Constraint::Length(1),
+        Constraint::Min(1),
+        Constraint::Length(3),
+    ])
+    .split(f.area());
+
+    draw_top(f, rows[0], app, theme);
+
+    let body = Layout::horizontal([Constraint::Min(1), Constraint::Length(theme.roster_width)])
+        .split(rows[1]);
+    draw_chat(f, body[0], app, theme);
+    draw_roster(f, body[1], app, theme);
+    draw_input(f, rows[2], app, theme);
+}
+
+fn draw_top(f: &mut Frame, area: ratatui::layout::Rect, app: &App, theme: &Theme) {
+    let cap = if app.capacity > 0 { app.capacity } else { app.users.len() };
+    let status = if app.connected { "🔒 e2e" } else { "✖ closed" };
+    let bar = Line::from(vec![
+        Span::styled(
+            " ⛧ hack-house ⛧ ",
+            Style::default().fg(theme.accent).add_modifier(Modifier::BOLD),
+        ),
+        Span::styled(format!("· {status} "), Style::default().fg(theme.dim)),
+        Span::styled(
+            format!("· house {}/{} ", app.users.len(), cap),
+            Style::default().fg(theme.title),
+        ),
+    ]);
+    f.render_widget(Paragraph::new(bar), area);
+}
+
+fn fmt_line<'a>(l: &'a ChatLine, app: &App, theme: &Theme) -> Line<'a> {
+    if l.system {
+        return Line::from(Span::styled(
+            format!("  ⛧ {}", l.text),
+            Style::default().fg(theme.system).add_modifier(Modifier::ITALIC),
+        ));
+    }
+    let name_color = if l.username == app.me { theme.me } else { theme.other };
+    Line::from(vec![
+        Span::styled(format!("{} ", l.ts), Style::default().fg(theme.dim)),
+        Span::styled(
+            l.username.clone(),
+            Style::default().fg(name_color).add_modifier(Modifier::BOLD),
+        ),
+        Span::styled(": ", Style::default().fg(theme.dim)),
+        Span::styled(l.text.as_str(), Style::default().fg(theme.title)),
+    ])
+}
+
+fn draw_chat(f: &mut Frame, area: ratatui::layout::Rect, app: &App, theme: &Theme) {
+    let visible = area.height.saturating_sub(2) as usize;
+    let start = app.lines.len().saturating_sub(visible);
+    let lines: Vec<Line> = app.lines[start..].iter().map(|l| fmt_line(l, app, theme)).collect();
+    let chat = Paragraph::new(lines)
+        .block(
+            Block::bordered()
+                .border_style(Style::default().fg(theme.border))
+                .title(Span::styled(" chat ", Style::default().fg(theme.title))),
+        )
+        .wrap(Wrap { trim: false });
+    f.render_widget(chat, area);
+}
+
+fn draw_roster(f: &mut Frame, area: ratatui::layout::Rect, app: &App, theme: &Theme) {
+    let items: Vec<ListItem> = app
+        .users
+        .iter()
+        .map(|u| {
+            let me = u.username == app.me;
+            let mark = if me { "⛧" } else { "•" };
+            let color = if me { theme.roster_me } else { theme.other };
+            ListItem::new(Line::from(Span::styled(
+                format!(" {mark} {}", u.username),
+                Style::default().fg(color),
+            )))
+        })
+        .collect();
+    let roster = List::new(items).block(
+        Block::bordered()
+            .border_style(Style::default().fg(theme.border))
+            .title(Span::styled(" coven ", Style::default().fg(theme.title))),
+    );
+    f.render_widget(roster, area);
+}
+
+fn draw_input(f: &mut Frame, area: ratatui::layout::Rect, app: &App, theme: &Theme) {
+    let input = Paragraph::new(Line::from(vec![
+        Span::styled("> ", Style::default().fg(theme.accent)),
+        Span::styled(app.input.as_str(), Style::default().fg(theme.input)),
+    ]))
+    .block(
+        Block::bordered()
+            .border_style(Style::default().fg(theme.border))
+            .title(Span::styled(
+                " message · enter send · esc quit ",
+                Style::default().fg(theme.dim),
+            )),
+    );
+    f.render_widget(input, area);
+
+    // Cursor after the "> " prompt + current input.
+    let cx = area.x + 3 + app.input.chars().count() as u16;
+    let cy = area.y + 1;
+    if cx < area.x + area.width.saturating_sub(1) {
+        f.set_cursor_position(Position::new(cx, cy));
+    }
+}