feat(cli): implement sessions list command

src/cli/sessions.test.ts

@@ -0,0 +1,40 @@
+import { describe, it, expect, afterEach } from 'vitest';
+import { listSessions } from './sessions.js';
+import { SessionStore } from '../session/index.js';
+import { join } from 'path';
+import { tmpdir } from 'os';
+import { existsSync, unlinkSync } from 'fs';
+
+describe('sessions command', () => {
+  const dbPath = join(tmpdir(), 'flynn-test-sessions-cli.db');
+  let store: SessionStore;
+
+  afterEach(() => {
+    store?.close();
+    if (existsSync(dbPath)) unlinkSync(dbPath);
+  });
+
+  it('returns empty list when no sessions', () => {
+    store = new SessionStore(dbPath);
+    const sessions = listSessions(store);
+    expect(sessions).toEqual([]);
+  });
+
+  it('returns session IDs with message counts', () => {
+    store = new SessionStore(dbPath);
+    store.addMessage('telegram:123', { role: 'user', content: 'Hello' });
+    store.addMessage('telegram:123', { role: 'assistant', content: 'Hi' });
+    store.addMessage('tui:local', { role: 'user', content: 'Test' });
+
+    const sessions = listSessions(store);
+    expect(sessions).toHaveLength(2);
+
+    const telegramSession = sessions.find(s => s.id === 'telegram:123');
+    expect(telegramSession).toBeDefined();
+    expect(telegramSession!.messageCount).toBe(2);
+
+    const tuiSession = sessions.find(s => s.id === 'tui:local');
+    expect(tuiSession).toBeDefined();
+    expect(tuiSession!.messageCount).toBe(1);
+  });
+});