refactor: HL EVM signing via sonirico/go-hyperliquid SDK

hl_helper/node_modules/aes-js/src.ts/mode.ts

@@ -0,0 +1,21 @@
+
+import { AES } from "./aes.js";
+
+export abstract class ModeOfOperation {
+  readonly aes!: AES;
+  readonly name!: string;
+
+  constructor(name: string, key: Uint8Array, cls?: any) {
+    if (cls && !(this instanceof cls)) {
+      throw new Error(`${ name } must be instantiated with "new"`);
+    }
+
+    Object.defineProperties(this, {
+      aes: { enumerable: true, value: new AES(key) },
+      name: { enumerable: true, value: name }
+    });
+  }
+
+  abstract encrypt(plaintext: Uint8Array): Uint8Array;
+  abstract decrypt(ciphertext: Uint8Array): Uint8Array;
+}