feat: Replace aCAPTCHA with official ALTCHA (altcha.org) Proof-of-Work web component widget

frontend/node_modules/hash-wasm/lib/mutex.ts

@@ -0,0 +1,24 @@
+class Mutex {
+	private mutex = Promise.resolve();
+
+	lock(): PromiseLike<() => void> {
+		let begin: (unlock: () => void) => void = () => {};
+
+		this.mutex = this.mutex.then(() => new Promise(begin));
+
+		return new Promise((res) => {
+			begin = res;
+		});
+	}
+
+	async dispatch<T>(fn: () => PromiseLike<T>): Promise<T> {
+		const unlock = await this.lock();
+		try {
+			return await Promise.resolve(fn());
+		} finally {
+			unlock();
+		}
+	}
+}
+
+export default Mutex;