feat: add SessionManager for multi-frontend session handling

src/session/manager.test.ts

@@ -0,0 +1,61 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { SessionManager } from './manager.js';
+import { SessionStore } from './store.js';
+import { unlinkSync, existsSync } from 'fs';
+import { join } from 'path';
+import { tmpdir } from 'os';
+
+describe('SessionManager', () => {
+  const dbPath = join(tmpdir(), 'flynn-test-manager.db');
+  let store: SessionStore;
+  let manager: SessionManager;
+
+  beforeEach(() => {
+    store = new SessionStore(dbPath);
+    manager = new SessionManager(store);
+  });
+
+  afterEach(() => {
+    store.close();
+    if (existsSync(dbPath)) {
+      unlinkSync(dbPath);
+    }
+  });
+
+  it('creates sessions for different frontends', () => {
+    const telegramSession = manager.getSession('telegram', 'user-123');
+    const tuiSession = manager.getSession('tui', 'local');
+
+    expect(telegramSession.id).toBe('telegram:user-123');
+    expect(tuiSession.id).toBe('tui:local');
+  });
+
+  it('returns same session for same frontend and user', () => {
+    const session1 = manager.getSession('telegram', 'user-123');
+    const session2 = manager.getSession('telegram', 'user-123');
+
+    expect(session1).toBe(session2);
+  });
+
+  it('transfers session history between frontends', () => {
+    const telegramSession = manager.getSession('telegram', 'user-123');
+    telegramSession.addMessage({ role: 'user', content: 'Hello from Telegram' });
+    telegramSession.addMessage({ role: 'assistant', content: 'Hi!' });
+
+    const tuiSession = manager.getSession('tui', 'local');
+    manager.transferSession('telegram', 'user-123', 'tui', 'local');
+
+    const tuiMessages = tuiSession.getHistory();
+    expect(tuiMessages).toHaveLength(2);
+    expect(tuiMessages[0].content).toBe('Hello from Telegram');
+  });
+
+  it('lists active sessions', () => {
+    manager.getSession('telegram', 'user-123');
+    manager.getSession('tui', 'local');
+
+    const sessions = manager.listSessions();
+    expect(sessions).toContain('telegram:user-123');
+    expect(sessions).toContain('tui:local');
+  });
+});