feat: Square client dev mock for online payments and type additions

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/internal/square/square_dev.go

@@ -40,6 +40,9 @@ func (d *devProdClient) RefundPayment(ctx context.Context, req RefundPaymentReq)
 func (d *devProdClient) CreateCardOnFile(ctx context.Context, userID, cardToken string) (*CardOnFile, error) {
 	return nil, fmt.Errorf("square payments not yet configured — set SQUARE_ACCESS_TOKEN and SQUARE_LOCATION_ID in .env")
 }
+func (d *devProdClient) CreateCardOnFileRaw(ctx context.Context, userID, cardNumber string, expMonth, expYear int, cvc string) (*CardOnFile, error) {
+	return nil, fmt.Errorf("square payments not yet configured — set SQUARE_ACCESS_TOKEN and SQUARE_LOCATION_ID in .env")
+}
 func (d *devProdClient) GetCardsOnFile(ctx context.Context, userID string) ([]CardOnFile, error) {
 	return nil, fmt.Errorf("square payments not yet configured — set SQUARE_ACCESS_TOKEN and SQUARE_LOCATION_ID in .env")
 }
@@ -217,6 +220,39 @@ func (m *MockClient) CreateCardOnFile(ctx context.Context, userID, cardToken str
 	return card, nil
 }
 
+func (m *MockClient) CreateCardOnFileRaw(ctx context.Context, userID, cardNumber string, expMonth, expYear int, cvc string) (*CardOnFile, error) {
+	log.Printf("[SQUARE-MOCK] CreateCardOnFileRaw: user=%s", userID)
+
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.cards[userID] == nil {
+		m.cards[userID] = make(map[string]*CardOnFile)
+	}
+
+	cardID := fmt.Sprintf("mock_card_%d", time.Now().UnixNano())
+	last4 := cardNumber[len(cardNumber)-4:]
+	brands := map[string]string{"4": "VISA", "5": "MASTERCARD", "3": "AMEX", "6": "DISCOVER"}
+	brand := brands[string(cardNumber[0])]
+	if brand == "" {
+		brand = "VISA"
+	}
+
+	card := &CardOnFile{
+		ID:          cardID,
+		CardID:      "cfa_" + cardID,
+		Brand:       brand,
+		Last4:       last4,
+		ExpMonth:    expMonth,
+		ExpYear:     expYear,
+		Fingerprint: fmt.Sprintf("fp_%d", time.Now().UnixNano()),
+		IsDefault:   len(m.cards[userID]) == 0,
+	}
+	m.cards[userID][cardID] = card
+	log.Printf("[SQUARE-MOCK] Card created: id=%s, brand=%s, last4=%s", cardID, card.Brand, card.Last4)
+	return card, nil
+}
+
 func (m *MockClient) GetCardsOnFile(ctx context.Context, userID string) ([]CardOnFile, error) {
 	log.Printf("[SQUARE-MOCK] GetCardsOnFile: user=%s", userID)