chore: reorganize frontend into app and admin roots

app/src/lib/api.ts

@@ -0,0 +1,72 @@
+function isLoopbackHostname(hostname: string) {
+  return hostname === 'localhost' || hostname === '127.0.0.1';
+}
+
+function normalizeBaseUrl(baseUrl: string) {
+  return baseUrl.replace(/\/+$/, '');
+}
+
+function resolveApiBaseUrl() {
+  const configuredBaseUrl = (import.meta.env.VITE_API_BASE_URL ?? '').trim();
+
+  if (typeof window === 'undefined') {
+    return normalizeBaseUrl(configuredBaseUrl);
+  }
+
+  const fallbackBaseUrl = `${window.location.protocol}//${window.location.hostname}:4000/api`;
+
+  if (!configuredBaseUrl) {
+    return fallbackBaseUrl;
+  }
+
+  try {
+    const configuredUrl = new URL(configuredBaseUrl);
+
+    if (isLoopbackHostname(configuredUrl.hostname) && !isLoopbackHostname(window.location.hostname)) {
+      configuredUrl.hostname = window.location.hostname;
+      return normalizeBaseUrl(configuredUrl.toString());
+    }
+
+    return normalizeBaseUrl(configuredUrl.toString());
+  } catch {
+    return normalizeBaseUrl(configuredBaseUrl);
+  }
+}
+
+const apiBaseUrl = resolveApiBaseUrl();
+
+export const hasApiConfig = Boolean(apiBaseUrl);
+
+export async function apiRequest<T>(path: string, init?: RequestInit): Promise<T> {
+  if (!apiBaseUrl) {
+    throw new Error('VITE_API_BASE_URL is not configured.');
+  }
+
+  let response: Response;
+
+  try {
+    response = await fetch(`${apiBaseUrl}${path}`, {
+      credentials: 'include',
+      headers: {
+        'Content-Type': 'application/json',
+        ...(init?.headers ?? {}),
+      },
+      ...init,
+    });
+  } catch (error) {
+    throw new Error(
+      `Failed to reach the local API at ${apiBaseUrl}. Check that the API server is running and that VITE_API_BASE_URL matches the host you opened in the browser.`,
+      { cause: error },
+    );
+  }
+
+  const contentType = response.headers.get('content-type') || '';
+  const payload = contentType.includes('application/json') ? ((await response.json()) as unknown) : null;
+
+  if (!response.ok) {
+    const message = payload && typeof payload === 'object' && 'error' in payload ? String(payload.error) : 'Request failed.';
+    throw new Error(message);
+  }
+
+  return payload as T;
+}