feat(tui): ratatui skeleton with layout

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

crates/tui/src/main.rs

@@ -1 +1,41 @@
-fn main() {}
+use clap::Parser;
+
+mod app;
+mod ui;
+
+#[derive(Parser)]
+#[command(name = "log-viewer", about = "A log viewer TUI")]
+struct Cli {
+    /// Log files to open
+    files: Vec<String>,
+}
+
+fn main() -> anyhow::Result<()> {
+    let _cli = Cli::parse();
+
+    crossterm::terminal::enable_raw_mode()?;
+    let mut stdout = std::io::stdout();
+    crossterm::execute!(stdout, crossterm::terminal::EnterAlternateScreen)?;
+    let backend = ratatui::backend::CrosstermBackend::new(stdout);
+    let mut terminal = ratatui::Terminal::new(backend)?;
+
+    let mut app = app::App::new();
+
+    while !app.should_quit {
+        terminal.draw(|frame| ui::render(frame, &app))?;
+        if crossterm::event::poll(std::time::Duration::from_millis(100))?
+            && let crossterm::event::Event::Key(key) = crossterm::event::read()?
+        {
+            app.handle_key(key);
+        }
+    }
+
+    crossterm::terminal::disable_raw_mode()?;
+    crossterm::execute!(
+        terminal.backend_mut(),
+        crossterm::terminal::LeaveAlternateScreen
+    )?;
+    terminal.show_cursor()?;
+
+    Ok(())
+}