feat(commands,audit): add /context command and proactive compaction audit events

src/gateway/handlers/agent.test.ts

@@ -82,6 +82,25 @@ describe('createAgentHandlers command fast-path', () => {
     expect((event.data as { content: string }).content).toContain('Token Usage');
   });
 
+  it('handles /context command via fast-path', async () => {
+    const sent: OutboundMessage[] = [];
+    const send = vi.fn((msg: OutboundMessage) => sent.push(msg));
+    const req: GatewayRequest = {
+      id: 8,
+      method: 'agent.send',
+      params: { message: '/context', connectionId: 'conn-1' },
+    };
+
+    await handlers['agent.send'](req, send);
+
+    expect(mockAgent.process).not.toHaveBeenCalled();
+    expect(sent).toHaveLength(1);
+    const event = sent[0] as GatewayEvent;
+    expect(event.event).toBe('done');
+    expect((event.data as { content: string }).content).toContain('Context Usage');
+    expect((event.data as { content: string }).content).toContain('Compaction threshold');
+  });
+
   it('handles metadata commands via fast-path', async () => {
     const sent: OutboundMessage[] = [];
     const send = vi.fn((msg: OutboundMessage) => sent.push(msg));