Add OpenAPI docs, frontend, migrations, and API updates

- OpenAPI: add missing endpoints (add-from-url, subscriptions, public availability)
- OpenAPI: CalendarSubscription schema, Subscriptions tag
- Frontend app
- Migrations: count_for_availability, subscriptions_sync, user_preferences, calendar_settings
- Config, rate limit, auth, calendar, booking, ICS, availability, user service updates

Made-with: Cursor

frontend/node_modules/tapable/lib/SyncLoopHook.js

@@ -0,0 +1,46 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+"use strict";
+
+const Hook = require("./Hook");
+const HookCodeFactory = require("./HookCodeFactory");
+
+class SyncLoopHookCodeFactory extends HookCodeFactory {
+	content({ onError, onDone, rethrowIfPossible }) {
+		return this.callTapsLooping({
+			onError: (i, err) => onError(err),
+			onDone,
+			rethrowIfPossible
+		});
+	}
+}
+
+const factory = new SyncLoopHookCodeFactory();
+
+const TAP_ASYNC = () => {
+	throw new Error("tapAsync is not supported on a SyncLoopHook");
+};
+
+const TAP_PROMISE = () => {
+	throw new Error("tapPromise is not supported on a SyncLoopHook");
+};
+
+function COMPILE(options) {
+	factory.setup(this, options);
+	return factory.create(options);
+}
+
+function SyncLoopHook(args = [], name = undefined) {
+	const hook = new Hook(args, name);
+	hook.constructor = SyncLoopHook;
+	hook.tapAsync = TAP_ASYNC;
+	hook.tapPromise = TAP_PROMISE;
+	hook.compile = COMPILE;
+	return hook;
+}
+
+SyncLoopHook.prototype = null;
+
+module.exports = SyncLoopHook;