feat(agent-sdk): add basic usage example

sdks/typescript-agent-sdk/examples/basic.ts

@@ -0,0 +1,42 @@
+/**
+ * Basic example — Agent.create -> session.send -> stream -> wait.
+ *
+ * Run with:
+ *   LITELLM_API_KEY=sk-... LITELLM_BASE_URL=http://localhost:4000 \
+ *     npx tsx examples/basic.ts
+ */
+
+import { Agent } from "../src/index.js";
+
+async function main(): Promise<void> {
+  const agent = await Agent.create({
+    apiKey: process.env.LITELLM_API_KEY,
+    baseUrl: process.env.LITELLM_BASE_URL,
+    name: "basic-example",
+    model: { id: "claude-4.6-sonnet" },
+    systemPrompt: "You are a helpful assistant.",
+  });
+
+  console.log("agent created:", agent.id);
+
+  const session = await agent.createSession();
+  console.log("session created:", session.id);
+
+  const run = await session.send("Say hi in one short sentence.");
+  console.log("run started:", run.id);
+
+  for await (const event of run.stream()) {
+    console.log(`[${event.seq}] ${event.type}`, event.data);
+  }
+
+  const result = await run.wait();
+  console.log("final status:", result.status);
+  console.log("result:", result.result);
+
+  await session.delete();
+}
+
+main().catch((err) => {
+  console.error(err);
+  process.exit(1);
+});