Initial commit: React frontend (SLP Software) + AIDLC workflow docs

Co-authored-by: Junie <junie@jetbrains.com>

src/queryClient.ts

@@ -0,0 +1,15 @@
+import { QueryClient } from '@tanstack/react-query';
+
+/**
+ * Single shared QueryClient. staleTime is set to Infinity by default because, for now,
+ * all queries (see src/hooks/usePackagesQuery.ts) resolve static local data — there is
+ * no real network staleness yet. Revisit once a real backend exists (requirements FR-5).
+ */
+export const queryClient = new QueryClient({
+  defaultOptions: {
+    queries: {
+      staleTime: Infinity,
+      refetchOnWindowFocus: false,
+    },
+  },
+});