feat(lib): add OpenRouter client implementation

src/lib/openrouter-client.ts

@@ -0,0 +1,9 @@
+import { OpenRouter } from "@openrouter/sdk";
+
+if (!process.env.OPENROUTER_API_KEY) {
+	throw new Error("OPENROUTER_API_KEY environment variable is not set");
+}
+
+export const openRouterClient = new OpenRouter({
+	apiKey: process.env.OPENROUTER_API_KEY,
+});