feat: add k-launcher-ui-egui crate for enhanced UI

- Introduced a new crate `k-launcher-ui-egui` to provide a graphical user interface using eframe and egui.
- Updated the workspace configuration in `Cargo.toml` to include the new crate.
- Implemented the main application logic in `src/app.rs`, handling search functionality and user interactions.
- Created a library entry point in `src/lib.rs` to expose the `run` function for launching the UI.
- Modified the `k-launcher` crate to include a new binary target for the egui-based launcher.
- Added a new main file `src/main_egui.rs` to initialize and run the egui UI with the existing kernel and launcher components.

crates/k-launcher-ui-egui/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "k-launcher-ui-egui"
+version = "0.1.0"
+edition = "2024"
+
+[lib]
+name = "k_launcher_ui_egui"
+path = "src/lib.rs"
+
+[dependencies]
+eframe = { version = "0.31", default-features = false, features = ["default_fonts", "wayland", "x11", "glow"] }
+egui = "0.31"
+k-launcher-kernel = { path = "../k-launcher-kernel" }
+k-launcher-os-bridge = { path = "../k-launcher-os-bridge" }
+tokio = { workspace = true }