feat(initial): scaffold @push.rocks/smartchat with core, CLI, and web layers

Three-layer architecture built on @push.rocks/smartagent:
- ts/ — ChatSession wrapping runAgent() with conversation state management
- ts_cli/ — ink-based terminal chat TUI (React.createElement, no JSX)
- ts_web/ — Lit web components (smartchat-window, smartchat-message, smartchat-input)

test/test.ts

@@ -0,0 +1,45 @@
+import { expect, tap } from '@git.zone/tstest/tapbundle';
+import * as smartchat from '../ts/index.js';
+
+tap.test('should export ChatSession class', async () => {
+  expect(smartchat.ChatSession).toBeTypeOf('function');
+});
+
+tap.test('ChatSession should initialize with options', async () => {
+  // Use a mock model (just needs to be an object)
+  const mockModel = {} as any;
+  const session = new smartchat.ChatSession({ model: mockModel });
+  expect(session).toBeInstanceOf(smartchat.ChatSession);
+});
+
+tap.test('ChatSession should track usage', async () => {
+  const mockModel = {} as any;
+  const session = new smartchat.ChatSession({ model: mockModel });
+  const usage = session.getUsage();
+  expect(usage.turns).toEqual(0);
+  expect(usage.totalTokens).toEqual(0);
+});
+
+tap.test('ChatSession should manage messages', async () => {
+  const mockModel = {} as any;
+  const session = new smartchat.ChatSession({ model: mockModel });
+
+  expect(session.getMessages()).toHaveLength(0);
+
+  // Set messages
+  const fakeMessages = [{ role: 'user' as const, content: 'hello' }] as any[];
+  session.setMessages(fakeMessages);
+  expect(session.getMessages()).toHaveLength(1);
+
+  // Clear
+  session.clear();
+  expect(session.getMessages()).toHaveLength(0);
+});
+
+tap.test('ChatSession should report busy state', async () => {
+  const mockModel = {} as any;
+  const session = new smartchat.ChatSession({ model: mockModel });
+  expect(session.isBusy()).toBeFalse();
+});
+
+export default tap.start();