feat(cards): add input masks and char limits to card form fields

- Card number: groups of 4 digits (0000 0000 0000 0000), max 16 digits
- Expiry: MM/AAAA mask, max 6 digits
- CVV: digits only, max 4
- CPF: 000.000.000-00 mask, max 11 digits
- canSubmit validates stripped digit counts

pedi-foods/Sources/PediFoods/Views/Main/CheckoutView.swift

@@ -997,10 +997,10 @@ struct PaymentCardView: View {
     }
 
     var canSubmit: Bool {
-        holderName.isEmpty == false &&
+        holderName.trimmingCharacters(in: .whitespaces).isEmpty == false &&
         cardNumber.filter(\.isNumber).count >= 13 &&
-        expiry.count >= 4 &&
+        expiry.filter(\.isNumber).count == 6 &&
-        cvv.count >= 3 &&
+        cvv.filter(\.isNumber).count >= 3 &&
         cpf.filter(\.isNumber).count == 11
     }
 
@@ -1051,15 +1051,49 @@ struct PaymentCardView: View {
                     VStack(spacing: 10) {
                         labeledField("Número do Cartão", placeholder: "0000 0000 0000 0000", text: $cardNumber)
                             .keyboardType(.numberPad)
+                            .onChange(of: cardNumber) { _, v in
+                                let d = String(v.filter(\.isNumber).prefix(16))
+                                let masked = stride(from: 0, to: d.count, by: 4)
+                                    .map { i -> String in
+                                        let start = d.index(d.startIndex, offsetBy: i)
+                                        let end = d.index(start, offsetBy: min(4, d.count - i))
+                                        return String(d[start..<end])
+                                    }.joined(separator: " ")
+                                if masked != v { cardNumber = masked }
+                            }
+
                         labeledField("Nome no Cartão", placeholder: "Como impresso no cartão", text: $holderName)
+
                         HStack(spacing: 10) {
                             labeledField("Validade", placeholder: "MM/AAAA", text: $expiry)
                                 .keyboardType(.numberPad)
+                                .onChange(of: expiry) { _, v in
+                                    let d = String(v.filter(\.isNumber).prefix(6))
+                                    let masked: String
+                                    if d.count <= 2 { masked = d }
+                                    else { masked = "\(d.prefix(2))/\(d.dropFirst(2))" }
+                                    if masked != v { expiry = masked }
+                                }
+
                             labeledField("CVV", placeholder: "•••", text: $cvv)
                                 .keyboardType(.numberPad)
+                                .onChange(of: cvv) { _, v in
+                                    let d = String(v.filter(\.isNumber).prefix(4))
+                                    if d != v { cvv = d }
                                 }
+                        }
+
                         labeledField("CPF do Titular", placeholder: "000.000.000-00", text: $cpf)
                             .keyboardType(.numberPad)
+                            .onChange(of: cpf) { _, v in
+                                let d = String(v.filter(\.isNumber).prefix(11))
+                                let masked: String
+                                if d.count <= 3 { masked = d }
+                                else if d.count <= 6 { masked = "\(d.prefix(3)).\(d.dropFirst(3))" }
+                                else if d.count <= 9 { masked = "\(d.prefix(3)).\(d.dropFirst(3).prefix(3)).\(d.dropFirst(6))" }
+                                else { masked = "\(d.prefix(3)).\(d.dropFirst(3).prefix(3)).\(d.dropFirst(6).prefix(3))-\(d.dropFirst(9))" }
+                                if masked != v { cpf = masked }
+                            }
                     }
                     .padding(14)
                 }