fix: make settings panel scrollable (html/body height:100%), bump window size, robust load

src/main.ts

@@ -527,7 +527,7 @@ export default function () {
     }
   })
 
-  showUI({ width: 320, height: 200, themeColors: true, title: 'AI assistant (MVP)' })
+  showUI({ width: 380, height: 480, themeColors: true, title: 'AI assistant (MVP)' })
 
   // Restore persisted window placement (saved in clientStorage on the Figma file).
   // Default when nothing is stored: behave like the Center button (50% viewport, centered).