API client, auth bootstrap and job polling (#42)

Co-authored-by: dev_agent <dev_agent@cubecraftlabs.com>
Co-committed-by: dev_agent <dev_agent@cubecraftlabs.com>

web/src/api/queryClient.ts

@@ -0,0 +1,20 @@
+import { QueryClient } from '@tanstack/react-query'
+import { ApiError } from './errors.ts'
+
+// MAX_RETRIES bounds retries of a failure the server marked retryable.
+export const MAX_RETRIES = 3
+
+// shouldRetry retries only an ApiError the server marked retryable — never a
+// 401, a 403 or a malformed response.
+export function shouldRetry(failureCount: number, error: unknown): boolean {
+  return error instanceof ApiError && error.retryable && failureCount < MAX_RETRIES
+}
+
+export function createQueryClient(): QueryClient {
+  return new QueryClient({
+    defaultOptions: {
+      queries: { retry: shouldRetry, staleTime: 30_000 },
+      mutations: { retry: shouldRetry },
+    },
+  })
+}