feat: add list command to retrieve and paginate user files

lib/b64.ts

@@ -0,0 +1,12 @@
+// i actually love this
+export const b64encode = (obj: object): string => {
+    return Buffer.from(JSON.stringify(obj)).toString("base64url");
+}
+
+export const b64decode = <T>(str: string): T => {
+    try {
+        return JSON.parse(Buffer.from(str, "base64url").toString());
+    } catch {
+        throw new Error("invalid base64-encoded object string: " + str);
+    }
+}