Add createStreamFn for CORS proxy support

- createStreamFn(proxyUrl?) returns a sync streamFn that applies proxy
- Example reads proxy settings once when creating Agent
- Matches old ProviderTransport behavior

packages/web-ui/example/src/main.ts

@@ -8,6 +8,7 @@ import {
 	ChatPanel,
 	CustomProvidersStore,
 	createJavaScriptReplTool,
+	createStreamFn,
 	IndexedDBStorageBackend,
 	// PersistentStorageDialog, // TODO: Fix - currently broken
 	ProviderKeysStore,
@@ -160,6 +161,10 @@ const createAgent = async (initialState?: Partial<AgentState>) => {
 		agentUnsubscribe();
 	}
 
+	// Read proxy settings for streamFn
+	const proxyEnabled = await storage.settings.get<boolean>("proxy.enabled");
+	const proxyUrl = proxyEnabled ? (await storage.settings.get<string>("proxy.url")) || undefined : undefined;
+
 	agent = new Agent({
 		initialState: initialState || {
 			systemPrompt: `You are a helpful AI assistant with access to various tools.
@@ -181,6 +186,8 @@ Feel free to use these tools when needed to provide accurate and helpful respons
 			const key = await storage.providerKeys.get(provider);
 			return key ?? undefined;
 		},
+		// Use streamFn with CORS proxy support
+		streamFn: createStreamFn(proxyUrl),
 	});
 
 	agentUnsubscribe = agent.subscribe((event: any) => {