feat(session): add optional end-of-session summarization

src/session/endSummary.test.ts

@@ -0,0 +1,76 @@
+import { describe, it, expect, vi } from 'vitest';
+import type { AgentOrchestrator } from '../backends/native/orchestrator.js';
+import { summarizeSessionOnEnd, sessionEndSummaryInternals } from './endSummary.js';
+import type { MemoryStore } from '../memory/store.js';
+
+describe('session end summary', () => {
+  it('sanitizes session ids for memory namespaces', () => {
+    expect(sessionEndSummaryInternals.sanitizeSessionId('ws:abc-123')).toBe('ws/abc-123');
+    expect(sessionEndSummaryInternals.sanitizeSessionId('telegram:user@x')).toBe('telegram/user_x');
+  });
+
+  it('summarizes and writes to memory when enabled', async () => {
+    const agent = {
+      delegate: vi.fn().mockResolvedValue({
+        content: '- User prefers concise responses.\n- Next step: run deploy tomorrow.',
+        usage: { inputTokens: 10, outputTokens: 8 },
+        tier: 'fast',
+      }),
+    } as unknown as AgentOrchestrator;
+    const memoryStore = {
+      write: vi.fn(),
+    } as unknown as MemoryStore;
+
+    const result = await summarizeSessionOnEnd({
+      agent,
+      sessionId: 'ws:conn-1',
+      history: [
+        { role: 'user', content: 'Please keep answers concise.' },
+        { role: 'assistant', content: 'Noted.' },
+      ],
+      config: {
+        enabled: true,
+        tier: 'fast',
+        maxMessages: 50,
+        maxInputChars: 20000,
+        maxTokens: 512,
+        writeToMemory: true,
+        memoryNamespace: 'session/summaries',
+      },
+      memoryStore,
+    });
+
+    expect(agent.delegate).toHaveBeenCalledTimes(1);
+    expect(result?.summary).toContain('concise');
+    expect(result?.namespace).toBe('session/summaries/ws/conn-1');
+    expect(memoryStore.write).toHaveBeenCalledWith(
+      'session/summaries/ws/conn-1',
+      expect.stringContaining('User prefers concise responses'),
+      'append',
+    );
+  });
+
+  it('skips when disabled', async () => {
+    const agent = {
+      delegate: vi.fn(),
+    } as unknown as AgentOrchestrator;
+
+    const result = await summarizeSessionOnEnd({
+      agent,
+      sessionId: 'ws:conn-1',
+      history: [{ role: 'user', content: 'hello' }],
+      config: {
+        enabled: false,
+        tier: 'fast',
+        maxMessages: 50,
+        maxInputChars: 20000,
+        maxTokens: 512,
+        writeToMemory: true,
+        memoryNamespace: 'session/summaries',
+      },
+    });
+
+    expect(result).toBeNull();
+    expect(agent.delegate).not.toHaveBeenCalled();
+  });
+});