fix: critical tool registration bug - ChatPanel.setAgent() was overwriting all tools

ROOT CAUSE: agent.setTools() registered 8 tools (bash, browser, web-search,
image-gen, tts, memory, repl), then chatPanel.setAgent(agent) with no config
called this.agent.setTools([artifactsTool]) internally, OVERWRITING all tools.

FIX: Pass tools via toolsFactory config parameter so ChatPanel merges them
with its own artifacts tool instead of replacing them.

This fixes all 'Tool X not found' errors in the web UI.

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

@@ -406,9 +406,11 @@ Persist information across sessions. Use to save important context, user prefere
 			renderApp();
 		},
 	});
-	// Register tools with the agent
+	// Register tools via toolsFactory so ChatPanel includes them alongside its artifacts tool
 	const replTool = createJavaScriptReplTool();
-	agent.setTools([
+	costTracker.bindAgent(agent);
+	chatPanel?.setAgent(agent, {
+		toolsFactory: () => [
 			replTool,
 			createWebSearchTool(),
 			createBashTool(),
@@ -416,9 +418,8 @@ Persist information across sessions. Use to save important context, user prefere
 			createImageGenTool(),
 			createTTSTool(),
 			...createMemoryTools(),
-	]);
-	costTracker.bindAgent(agent);
-	chatPanel?.setAgent(agent);
+		],
+	});
 	// Hook: live model badge + immediate empty state hide
 	requestAnimationFrame(() => {
 		if (chatPanel?.agentInterface) {