Feat: Implement splash screen with progress indicators during startup

app/splashManager.js

@@ -0,0 +1,37 @@
+const { BrowserWindow } = require("electron");
+const path = require("path");
+
+let splashWindow = null;
+
+function createSplashWindow() {
+  splashWindow = new BrowserWindow({
+    width: 400,
+    height: 300,
+    frame: false,
+    transparent: true,
+    alwaysOnTop: true,
+    resizable: false,
+    skipTaskbar: true,
+    webPreferences: {
+      nodeIntegration: false,
+      contextIsolation: true,
+    },
+  });
+
+  splashWindow.loadFile(path.join(__dirname, "../public/splash.html"));
+}
+
+function closeSplashWindow() {
+  if (splashWindow) {
+    splashWindow.close();
+    splashWindow = null;
+  }
+}
+
+function setSplashProgress(step) {
+  if (splashWindow) {
+    splashWindow.webContents.executeJavaScript(`window.setProgress(${step})`);
+  }
+}
+
+module.exports = { createSplashWindow, closeSplashWindow, setSplashProgress };