feat: add ExamStageActions component for exam fee handling

- Implemented ExamStageActions component to manage actions related to exam booking and payment based on application status.
- Added mock-base-query for development, providing a partial mock backend for various API endpoints.
- Introduced mock-data for simulating responses in the mock-base-query, covering profiles, vessels, applications, licenses, exams, and notifications.

libs/api/src/lib/base-api/index.ts

@@ -1,9 +1,17 @@
 import { createApi } from "@reduxjs/toolkit/query/react";
 import { baseQueryWithReauth } from "./base-query-with-reauth";
+import { mockBaseQuery } from "./mock-base-query";
 import { tagTypes } from "./tagTypes";
+
+// Dev-only preview mode: set VITE_USE_MOCKS=true (repo-root .env.local) to
+// serve the four preview feature areas from static sample data instead of a
+// live backend. See mock-base-query.ts for what is and isn't covered.
+const useMocks =
+  (import.meta as { env?: Record<string, string> }).env?.["VITE_USE_MOCKS"] === "true";
+
 export const baseApi = createApi({
   reducerPath: "baseApi",
-  baseQuery: baseQueryWithReauth,
+  baseQuery: useMocks ? mockBaseQuery : baseQueryWithReauth,
   tagTypes: ["Api", "backOfficeApi", "portalApi", ...tagTypes],
   endpoints: () => ({}),
 });