Initial project setup with multi-component architecture

- Initialize TypeScript project with pnpm
- Create agent, gateway, client, and shared modules
- Configure ESM with strict TypeScript settings

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/client/client.ts

@@ -0,0 +1,3 @@
+export class Client {
+  constructor(public readonly id: string) {}
+}

src/client/index.ts

@@ -0,0 +1 @@
+export * from "./client.js";