Add real-time viewer count component and integrate it into stream page; update presence tracking logic with Jazz.

packages/web/src/lib/jazz/provider.tsx

@@ -0,0 +1,28 @@
+import { JazzReactProvider } from "jazz-tools/react"
+import { ViewerAccount } from "./schema"
+
+// Jazz Cloud API key - using public demo key for now
+// TODO: Replace with linsa-specific key from https://jazz.tools
+const JAZZ_API_KEY = "jazz_cloud_demo"
+
+interface JazzProviderProps {
+  children: React.ReactNode
+}
+
+/**
+ * Jazz provider for stream viewer presence tracking
+ * Uses anonymous auth - viewers don't need to sign in
+ */
+export function JazzProvider({ children }: JazzProviderProps) {
+  return (
+    <JazzReactProvider
+      sync={{
+        peer: `wss://cloud.jazz.tools/?key=${JAZZ_API_KEY}`,
+        when: "always",
+      }}
+      AccountSchema={ViewerAccount}
+    >
+      {children}
+    </JazzReactProvider>
+  )
+}