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/rollup/dist/shared/fsevents-importer.js

@@ -0,0 +1,37 @@
+/*
+  @license
+	Rollup.js v4.59.0
+	Sun, 22 Feb 2026 07:31:53 GMT - commit ae846957f109690a866cc3e4c073613c338d3476
+
+	https://github.com/rollup/rollup
+
+	Released under the MIT License.
+*/
+'use strict';
+
+let fsEvents;
+let fsEventsImportError;
+async function loadFsEvents() {
+    try {
+        ({ default: fsEvents } = await import('fsevents'));
+    }
+    catch (error) {
+        fsEventsImportError = error;
+    }
+}
+// A call to this function will be injected into the chokidar code
+function getFsEvents() {
+    if (fsEventsImportError)
+        throw fsEventsImportError;
+    return fsEvents;
+}
+
+const fseventsImporter = /*#__PURE__*/Object.defineProperty({
+    __proto__: null,
+    getFsEvents,
+    loadFsEvents
+}, Symbol.toStringTag, { value: 'Module' });
+
+exports.fseventsImporter = fseventsImporter;
+exports.loadFsEvents = loadFsEvents;
+//# sourceMappingURL=fsevents-importer.js.map