H-116: close visitor payload trust boundaries (#19)

* H-116: close visitor payload trust boundaries

* H-129: unblock SQLite backend tests

* H-129: remove stale last-seen response assertions

---------

Co-authored-by: Rogee <rogee@ipao.vip>

backend/internal/service/agent_bot_listener.go

@@ -294,7 +294,8 @@ func agentBotWebhookPayload(eventType string, accountID uint, inboxID uint, data
 	if _, ok := payload["inbox_id"]; !ok {
 		payload["inbox_id"] = inboxID
 	}
-	return payload
+	sanitized, _ := webhookutil.SanitizeOutbound(payload).(map[string]interface{})
+	return sanitized
 }
 
 // pushToBot sends the webhook payload to a single bot's outgoing_url with Chatwoot webhook headers.

backend/internal/service/agent_bot_listener_test.go

@@ -106,10 +106,15 @@ func TestAgentBotListenerSendsChatwootStyleTopLevelPayload(t *testing.T) {
 
 	listener := NewAgentBotListener(repository.NewAgentBotInboxRepo(db), repository.NewAgentBotRepo(db), nil, nil)
 	err := listener.HandleEvent(context.Background(), "message_created", account.ID, inbox.ID, map[string]interface{}{
-		"id":      float64(123),
-		"content": "hello bot",
+		"id":                 float64(123),
+		"content":            "hello bot",
+		"sender_id":          float64(7),
+		"sender_type":        "AgentBot",
+		"ai_takeover_active": true,
+		"content_attributes": []interface{}{map[string]interface{}{"business": "keep", "sender_name": "Captain"}},
 		"conversation": map[string]interface{}{
-			"id": float64(456),
+			"id":                    float64(456),
+			"assignee_agent_bot_id": float64(8),
 		},
 	})
 	require.NoError(t, err)
@@ -122,6 +127,13 @@ func TestAgentBotListenerSendsChatwootStyleTopLevelPayload(t *testing.T) {
 	assert.Equal(t, "hello bot", received["content"])
 	assert.NotContains(t, received, "data")
 	assert.NotContains(t, received, "timestamp")
+	assert.NotContains(t, string(receivedBody), "AgentBot")
+	assert.NotContains(t, string(receivedBody), "Captain")
+	assert.NotContains(t, string(receivedBody), "sender_")
+	assert.NotContains(t, string(receivedBody), "ai_takeover_")
+	assert.NotContains(t, string(receivedBody), "assignee_agent_bot_id")
+	attributes := received["content_attributes"].([]interface{})
+	assert.Equal(t, map[string]interface{}{"business": "keep"}, attributes[0])
 	assert.NotEmpty(t, receivedDelivery)
 	assert.Regexp(t, `^\d+$`, receivedTimestamp)
 	mac := hmac.New(sha256.New, []byte("secret"))