Add lastNobilityAdvanceAt field and update logic in FalukantService

- Introduced a new field `lastNobilityAdvanceAt` in the FalukantUser model to track the last time a user advanced in nobility.
- Updated the `FalukantService` to enforce a one-week cooldown between nobility advancements, throwing an error if the user attempts to advance too soon.
- Ensured the `lastNobilityAdvanceAt` field is updated with the current date upon a successful nobility advancement.

backend/migrations/20251126120000-add-last-nobility-advance-to-falukant-user.cjs

@@ -0,0 +1,29 @@
+'use strict';
+
+module.exports = {
+  up: async (queryInterface, Sequelize) => {
+    await queryInterface.addColumn(
+      {
+        tableName: 'falukant_user',
+        schema: 'falukant_data'
+      },
+      'last_nobility_advance_at',
+      {
+        type: Sequelize.DATE,
+        allowNull: true
+      }
+    );
+  },
+
+  down: async (queryInterface, Sequelize) => {
+    await queryInterface.removeColumn(
+      {
+        tableName: 'falukant_user',
+        schema: 'falukant_data'
+      },
+      'last_nobility_advance_at'
+    );
+  }
+};
+
+