feat: track received image outcomes

tests/dashboard/app.test.tsx

@@ -155,7 +155,7 @@ describe('dashboard foundation', () => {
       ),
       http.get('/api/messages', () => HttpResponse.json([{
         id: 1, postId: 'post-1', recipient: 'alice', subject: 'Hello', message: 'A recent opener',
-        sentAt: Date.now(), gotResponse: true, responseCheckedAt: Date.now(), strategyId: null, chatRoomId: null,
+        sentAt: Date.now(), gotResponse: true, gotImage: false, responseCheckedAt: Date.now(), strategyId: null, chatRoomId: null,
       }])),
     );