feat(frontend): add react spa with wishlist flows and public profile

apps/frontend/src/lib/api.ts

@@ -0,0 +1,70 @@
+export interface ApiErrorShape {
+  error: string;
+  message: string;
+  details?: unknown;
+}
+
+export class ApiError extends Error {
+  readonly status: number;
+  readonly code: string;
+  readonly details?: unknown;
+  constructor(status: number, body: ApiErrorShape) {
+    super(body.message);
+    this.status = status;
+    this.code = body.error;
+    this.details = body.details;
+  }
+}
+
+interface RequestOptions<TBody = unknown> {
+  method?: 'GET' | 'POST' | 'PATCH' | 'DELETE';
+  body?: TBody;
+  signal?: AbortSignal;
+  formData?: FormData;
+}
+
+async function request<TResponse, TBody = unknown>(
+  path: string,
+  options: RequestOptions<TBody> = {},
+): Promise<TResponse> {
+  const headers: Record<string, string> = {};
+  let body: BodyInit | undefined;
+
+  if (options.formData) {
+    body = options.formData;
+  } else if (options.body !== undefined) {
+    headers['content-type'] = 'application/json';
+    body = JSON.stringify(options.body);
+  }
+
+  const response = await fetch(path, {
+    method: options.method ?? 'GET',
+    headers,
+    body,
+    credentials: 'include',
+    signal: options.signal,
+  });
+
+  const isJson = response.headers.get('content-type')?.includes('application/json');
+  const payload = isJson ? await response.json().catch(() => null) : null;
+
+  if (!response.ok) {
+    const errBody: ApiErrorShape =
+      payload && typeof payload === 'object' && 'error' in payload
+        ? (payload as ApiErrorShape)
+        : { error: 'HTTP', message: response.statusText || 'Request failed' };
+    throw new ApiError(response.status, errBody);
+  }
+
+  return payload as TResponse;
+}
+
+export const api = {
+  get: <T>(path: string, signal?: AbortSignal) => request<T>(path, { signal }),
+  post: <T, B = unknown>(path: string, body?: B) => request<T, B>(path, { method: 'POST', body }),
+  patch: <T, B = unknown>(path: string, body?: B) =>
+    request<T, B>(path, { method: 'PATCH', body }),
+  delete: <T>(path: string) => request<T>(path, { method: 'DELETE' }),
+  upload: <T>(path: string, formData: FormData) =>
+    request<T>(path, { method: 'POST', formData }),
+};