feat: working file listing & saving

src/lib/consts.ts

@@ -0,0 +1 @@
+export const IS_DEV = process.env.NODE_ENV === "development";

src/lib/utils.ts

@@ -1,6 +1,10 @@
-import { type ClassValue, clsx } from "clsx"
-import { twMerge } from "tailwind-merge"
+import { type ClassValue, clsx } from "clsx";
+import { twMerge } from "tailwind-merge";
 
 export function cn(...inputs: ClassValue[]) {
-  return twMerge(clsx(inputs))
+  return twMerge(clsx(inputs));
+}
+
+export function getFileExt(filename: string) {
+  return filename.substring(filename.lastIndexOf(".") + 1);
 }