feat(harmony_tui): add initial TUI implementation with ratatui and crossterm

Add a new `harmony_tui` crate to initialize and run a text-based user interface (TUI) for the Harmony project using `ratatui` for rendering and `crossterm` for handling input. The `HarmonyTUI` struct initializes the terminal, enters a loop to render updates, and handles basic input events to exit. This commit sets up the foundation for further TUI development.

harmony-rs/harmony_tui/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "harmony_tui"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+harmony = { path = "../harmony" }
+log = { workspace = true }
+env_logger = { workspace = true }
+tokio = { workspace = true }
+ratatui = "0.29.0"
+crossterm = "0.28.1"
+color-eyre = "0.6.3"

harmony-rs/harmony_tui/src/lib.rs

@@ -0,0 +1,67 @@
+use std::io;
+use crossterm::event::{self, Event};
+use harmony::maestro::Maestro;
+use ratatui::{self, layout::Position, prelude::CrosstermBackend, Frame, Terminal};
+
+pub mod tui {
+    // Export any necessary modules or types from the internal tui module
+}
+
+/// Initializes the terminal UI with the provided Maestro instance.
+///
+/// # Arguments
+///
+/// * `maestro` - A reference to the Maestro instance containing registered scores.
+///
+/// # Example
+///
+/// ```rust
+/// use harmony;
+/// use harmony_tui::init;
+///
+/// #[harmony::main]
+/// pub async fn main(maestro: harmony::Maestro) {
+///     maestro.register(DeploymentScore::new("nginx-test", "nginx"));
+///     maestro.register(OKDLoadBalancerScore::new(&maestro.inventory, &maestro.topology));
+///     // Register other scores as needed
+///
+///     init(maestro).await.unwrap();
+/// }
+/// ```
+pub async fn init(maestro: Maestro) -> Result<(), Box<dyn std::error::Error>> {
+    HarmonyTUI::new(maestro).init().await
+}
+
+pub struct HarmonyTUI {
+    maestro: Maestro,
+}
+
+impl HarmonyTUI {
+    pub fn new(maestro: Maestro) -> Self {
+        HarmonyTUI { maestro }
+    }
+
+    pub async fn init(self) -> Result<(), Box<dyn std::error::Error>> {
+        color_eyre::install()?;
+        let backend = CrosstermBackend::new(io::stdout());
+        let mut terminal = Terminal::new(backend)?;
+
+        loop {
+            terminal.draw(|f| self.render(f))?;
+            if matches!(event::read()?, Event::Key(_)) {
+                break;
+            }
+        }
+
+        Ok(())
+    }
+
+    fn render(&self, frame: &mut Frame) {
+        let size = frame.area();
+        frame.set_cursor_position(Position::new(size.x / 2, size.y / 2));
+        frame.render_widget(
+            ratatui::widgets::Paragraph::new("Hello World"),
+            frame.area(),
+        );
+    }
+}