Initial commit: Aeroflot Flights Web - Angular 12 baseline

- Angular 12 application with PrimeNG components
- 5 existing Cypress e2e test suites
- SCSS styling with BEM naming convention
- i18n support (10 languages)
- Leaflet map integration
- Complete component hierarchy and routing structure

This baseline will be used for Angular → React migration.

ClientApp/node_modules/lodash/_stackClear.js

@@ -0,0 +1,15 @@
+var ListCache = require('./_ListCache');
+
+/**
+ * Removes all key-value entries from the stack.
+ *
+ * @private
+ * @name clear
+ * @memberOf Stack
+ */
+function stackClear() {
+  this.__data__ = new ListCache;
+  this.size = 0;
+}
+
+module.exports = stackClear;