feat(webchat): support image attachments

src/gateway/handlers/handlers.test.ts

@@ -323,7 +323,28 @@ describe('agent handlers', () => {
     expect(sent).toHaveLength(1);
   });
 
-  it('agent.send requires message', async () => {
+  it('agent.send accepts attachment-only requests', async () => {
+    const req: GatewayRequest = {
+      id: 12,
+      method: 'agent.send',
+      params: {
+        connectionId: 'conn-1',
+        attachments: [{ mimeType: 'image/png', data: 'iVBOR...' }],
+      },
+    };
+    const sent: OutboundMessage[] = [];
+    const send = vi.fn((msg: OutboundMessage) => sent.push(msg));
+
+    await handlers['agent.send'](req, send);
+
+    expect(mockAgent.process).toHaveBeenCalledWith('', [
+      { mimeType: 'image/png', data: 'iVBOR...', url: undefined, filename: undefined },
+    ]);
+    expect(sent).toHaveLength(1);
+    expect((sent[0] as GatewayEvent).event).toBe('done');
+  });
+
+  it('agent.send requires message or attachments', async () => {
     const req: GatewayRequest = { id: 2, method: 'agent.send', params: { connectionId: 'conn-1' } };
     const send = vi.fn();
     const result = await handlers['agent.send'](req, send) as GatewayError;