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/@babel/helper-module-transforms/lib/rewrite-this.js

@@ -0,0 +1,22 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = rewriteThis;
+var _core = require("@babel/core");
+var _traverse = require("@babel/traverse");
+let rewriteThisVisitor;
+function rewriteThis(programPath) {
+  if (!rewriteThisVisitor) {
+    rewriteThisVisitor = _traverse.visitors.environmentVisitor({
+      ThisExpression(path) {
+        path.replaceWith(_core.types.unaryExpression("void", _core.types.numericLiteral(0), true));
+      }
+    });
+    rewriteThisVisitor.noScope = true;
+  }
+  (0, _traverse.default)(programPath.node, rewriteThisVisitor);
+}
+
+//# sourceMappingURL=rewrite-this.js.map