revert: drop minWidth/minHeight (Figma rejects these keys); native floor stays

src/main.ts

@@ -475,9 +475,7 @@ export default function () {
     })
   })
 
-  // minWidth/minHeight=0 let the window shrink below Figma's default floor on resize.
-  // Not in the official typings for this @figma/plugin-typings version, so cast through any.
-  showUI({ width: 320, height: 200, minWidth: 0, minHeight: 0, themeColors: true, title: 'AI assistant (MVP)' } as any)
+  showUI({ width: 320, height: 200, 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).