Set minimum window size to prevent UI breakage (#1195)

This PR solves issue #1194 by setting a minimum height and width
    
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## Summary by cubic
Set a minimum window size to prevent UI breakage when the app is resized
too small. The BrowserWindow now enforces minWidth 800 and minHeight 500
so layouts stay stable and controls remain accessible.

<!-- End of auto-generated description by cubic. -->

src/main.ts

@@ -133,7 +133,9 @@ const createWindow = () => {
   // Create the browser window.
   mainWindow = new BrowserWindow({
     width: process.env.NODE_ENV === "development" ? 1280 : 960,
+    minWidth: 800,
     height: 700,
+    minHeight: 500,
     titleBarStyle: "hidden",
     titleBarOverlay: false,
     trafficLightPosition: {