feat(frontend): add 6 GET methods (batches, batch, claims, remits, providers, activity) + tests

vitest.config.ts

@@ -0,0 +1,21 @@
+import path from "node:path";
+import { defineConfig } from "vitest/config";
+import react from "@vitejs/plugin-react";
+
+export default defineConfig({
+  plugins: [react()],
+  resolve: {
+    alias: {
+      "@": path.resolve(__dirname, "./src"),
+    },
+  },
+  test: {
+    // Node 18+ exposes `Response` / `fetch` globals, so we don't need jsdom.
+    // VITE_API_BASE_URL must be set so the api module treats itself as
+    // configured; otherwise every GET would throw notConfiguredError before
+    // reaching the mocked fetch.
+    env: {
+      VITE_API_BASE_URL: "http://test.local",
+    },
+  },
+});