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/enhanced-resolve/lib/getInnerRequest.js

@@ -0,0 +1,39 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+/** @typedef {import("./Resolver")} Resolver */
+/** @typedef {import("./Resolver").ResolveRequest} ResolveRequest */
+
+/**
+ * @param {Resolver} resolver resolver
+ * @param {ResolveRequest} request string
+ * @returns {string} inner request
+ */
+module.exports = function getInnerRequest(resolver, request) {
+	if (
+		typeof request.__innerRequest === "string" &&
+		request.__innerRequest_request === request.request &&
+		request.__innerRequest_relativePath === request.relativePath
+	) {
+		return request.__innerRequest;
+	}
+	/** @type {string | undefined} */
+	let innerRequest;
+	if (request.request) {
+		innerRequest = request.request;
+		if (/^\.\.?(?:\/|$)/.test(innerRequest) && request.relativePath) {
+			innerRequest = resolver.join(request.relativePath, innerRequest);
+		}
+	} else {
+		innerRequest = request.relativePath;
+	}
+	// eslint-disable-next-line camelcase
+	request.__innerRequest_request = request.request;
+	// eslint-disable-next-line camelcase
+	request.__innerRequest_relativePath = request.relativePath;
+	return (request.__innerRequest = /** @type {string} */ (innerRequest));
+};