feat: add configuration management and panel rendering

- Introduced a new `Config` struct for loading application configuration from a TOML file.
- Added support for keybindings and panel configurations, including status widgets.
- Implemented `PtyTerminal` for handling pseudo-terminal interactions.
- Created a rendering module to manage the display of application windows, panels, and dropdowns.
- Refactored the main application loop to utilize the new configuration and rendering logic.
- Removed legacy code related to event handling and rendering from `main.rs`.

Cargo.toml

@@ -10,3 +10,8 @@ path = "src/main.rs"
 [dependencies]
 crossterm = { version = "0.28", features = ["event-stream"] }
 ratatui = "0.29"
+serde = { version = "1", features = ["derive"] }
+toml = "0.8"
+portable-pty = "0.8"
+vt100 = "0.15"
+anyhow = "1"