feat(splashscreen): implement a splash screen for application startup

This commit introduces a splash screen that enhances the user experience during application startup. It includes a new HTML file for the splash screen layout and a corresponding icon. The main application logic has been updated to close the splash screen once the main application is ready.

- Added a splash screen HTML and icon for improved visual feedback
- Updated main application logic to manage splash screen visibility
- Enhanced title bar branding with an image instead of SVG

src-tauri/src/main.rs

@@ -19,6 +19,18 @@ use git::{
     restore_to_commit, search_code_introductions, stage_files, stash_apply, stash_drop, stash_pop,
     stash_push, undo_last_commit, unstage_files,
 };
+use tauri::Manager;
+
+#[tauri::command]
+fn close_splashscreen(app: tauri::AppHandle) {
+    if let Some(window) = app.get_webview_window("main") {
+        let _ = window.show();
+        let _ = window.set_focus();
+    }
+    if let Some(window) = app.get_webview_window("splashscreen") {
+        let _ = window.close();
+    }
+}
 
 #[tokio::main]
 async fn main() {
@@ -97,7 +109,8 @@ async fn main() {
             cred_load,
             cred_save,
             cred_delete,
-            set_sync_badge
+            set_sync_badge,
+            close_splashscreen
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");