Moved the NodeJS version of the application to the app/ directory.

app/frontend/src/api.ts

@@ -0,0 +1,55 @@
+import type { LocationOption, SelectionState, UsageTemplate } from "./types";
+
+const json = async <T>(path: string): Promise<T> => {
+  const response = await fetch(path);
+  if (!response.ok) {
+    let details = "";
+    try {
+      const payload = (await response.json()) as { message?: string };
+      details = payload.message ?? "";
+    } catch {
+      // Ignore non-JSON error payloads.
+    }
+
+    throw new Error(details || `Request failed for ${path} (${response.status})`);
+  }
+
+  return (await response.json()) as T;
+};
+
+export const api = {
+  health: () => json<{ status: string; message?: string }>("/api/health"),
+  locations: () => json<LocationOption[]>("/api/locations"),
+  publishers: (location: string) => json<string[]>(`/api/publishers?location=${encodeURIComponent(location)}`),
+  offers: (location: string, publisher: string) =>
+    json<string[]>(`/api/offers?location=${encodeURIComponent(location)}&publisher=${encodeURIComponent(publisher)}`),
+  skus: (location: string, publisher: string, offer: string) =>
+    json<string[]>(
+      `/api/skus?location=${encodeURIComponent(location)}&publisher=${encodeURIComponent(publisher)}&offer=${encodeURIComponent(offer)}`
+    ),
+  versions: (location: string, publisher: string, offer: string, sku: string) =>
+    json<string[]>(
+      `/api/versions?location=${encodeURIComponent(location)}&publisher=${encodeURIComponent(publisher)}&offer=${encodeURIComponent(offer)}&sku=${encodeURIComponent(sku)}`
+    ),
+  templates: () => json<UsageTemplate[]>("/api/templates"),
+  render: async (templateFile: string, selection: SelectionState): Promise<string> => {
+    const response = await fetch("/api/render", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({ templateFile, selection })
+    });
+
+    if (!response.ok) {
+      throw new Error("Failed to render template");
+    }
+
+    const payload = (await response.json()) as { rendered: string };
+    return payload.rendered;
+  },
+  skuExport: async (location: string, publisher: string, offer: string): Promise<string> => {
+    const payload = await json<{ rendered: string }>(
+      `/api/sku-export?location=${encodeURIComponent(location)}&publisher=${encodeURIComponent(publisher)}&offer=${encodeURIComponent(offer)}`
+    );
+    return payload.rendered;
+  }
+};