fix: restore backdrop-filter blur in production builds

Lightning CSS was deduplicating manually written backdrop-filter +
-webkit-backdrop-filter to just the webkit version, breaking blur on
Firefox. Remove manual webkit prefixes and let Lightning CSS auto-prefix
via browser targets in vite.config.ts.

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "homepage",
-	"version": "1.6.0",
+	"version": "1.6.1",
 	"private": true,
 	"type": "module",
 	"scripts": {