Add useAnalytics hook with server-safe NoopAnalytics fallback

src/observability/analytics/provider.tsx

@@ -0,0 +1,23 @@
+import { createContext, useContext } from "react";
+import type { Analytics } from "./types.js";
+
+const NOOP_ANALYTICS: Analytics = {
+  track() {},
+  page() {},
+};
+
+/**
+ * React context for the Analytics instance.
+ * Exported for use by AnalyticsLoader (which sets the provider value).
+ */
+export const AnalyticsContext = createContext<Analytics | null>(null);
+
+/**
+ * Returns the Analytics instance from context.
+ * Server-side and before AnalyticsLoader initializes: returns NoopAnalytics.
+ * Client-side after init: returns the real facade instance.
+ */
+export function useAnalytics(): Analytics {
+  const analytics = useContext(AnalyticsContext);
+  return analytics ?? NOOP_ANALYTICS;
+}