fix: merge duplicate CSS transition declarations in GridItem

- Combined duplicate transition properties into single declaration
- Fixes issue where width/height transitions were overwritten
- All four properties (width, height, transform, opacity) now animate correctly

Author: viktorius007

src/lib/GridItem.svelte

@@ -560,8 +560,7 @@
 	.item-default {
 		transition:
 			width 0.2s,
-			height 0.2s;
-		transition:
+			height 0.2s,
 			transform 0.2s,
 			opacity 0.2s;
 	}