Tauri desktop shell (reuses web/ frontend, connects to OpenAI-compatible endpoint, isolated in desktop/) (#24)

* Add Tauri desktop shell

* Update desktop setup after web UI merge

* Declare desktop bundle icons

desktop/src-tauri/src/lib.rs

@@ -0,0 +1,6 @@
+#[cfg_attr(mobile, tauri::mobile_entry_point)]
+pub fn run() {
+    tauri::Builder::default()
+        .run(tauri::generate_context!())
+        .expect("failed to run the colibri desktop application");
+}

desktop/src-tauri/src/main.rs

@@ -0,0 +1,5 @@
+#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
+
+fn main() {
+    colibri_desktop_lib::run();
+}