feat(captain): align task payload persistence

internal/repository/copilot_message_repo_test.go

@@ -53,6 +53,47 @@ func TestCopilotMessageRepo_Create(t *testing.T) {
 	assert.Equal(t, model.CopilotMessageTypeUser, msg.MessageType)
 }
 
+func TestCopilotMessageRepo_Create_AllowsChatwootMessageKeys(t *testing.T) {
+	db := setupTestDB(t, &model.CopilotThread{}, &model.CopilotMessage{})
+	repo := NewCopilotMessageRepo(db)
+	thread := createTestCopilotThread(t, db, 1, 1, "Tool Thread")
+	message, _ := json.Marshal(map[string]interface{}{
+		"content":          "Looking up docs",
+		"reasoning":        "Need product data",
+		"function_name":    "search_documentation",
+		"reply_suggestion": "Try this reply",
+	})
+
+	err := repo.Create(context.Background(), &model.CopilotMessage{
+		AccountID:       1,
+		CopilotThreadID: thread.ID,
+		MessageType:     model.CopilotMessageTypeAssistant,
+		Message:         message,
+	})
+
+	require.NoError(t, err)
+}
+
+func TestCopilotMessageRepo_Create_RejectsUnknownMessageKeys(t *testing.T) {
+	db := setupTestDB(t, &model.CopilotThread{}, &model.CopilotMessage{})
+	repo := NewCopilotMessageRepo(db)
+	thread := createTestCopilotThread(t, db, 1, 1, "Bad Tool Thread")
+	message, _ := json.Marshal(map[string]interface{}{
+		"content": "hello",
+		"unknown": "bad",
+	})
+
+	err := repo.Create(context.Background(), &model.CopilotMessage{
+		AccountID:       1,
+		CopilotThreadID: thread.ID,
+		MessageType:     model.CopilotMessageTypeAssistant,
+		Message:         message,
+	})
+
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "invalid attribute: unknown")
+}
+
 // --- 2. GetByID ---
 func TestCopilotMessageRepo_GetByID(t *testing.T) {
 	db := setupTestDB(t, &model.CopilotThread{}, &model.CopilotMessage{})
@@ -181,4 +222,4 @@ func TestCopilotMessageRepo_DeleteByThread(t *testing.T) {
 	require.NoError(t, errAfter)
 	assert.Equal(t, int64(0), countAfter)
 	assert.Len(t, msgsAfter, 0)
-}
+}