feat: add and enhance PermitsScreen and RequestPermitModal

- add LoadingScreen component
- update utilities

utils/dateTime.ts

@@ -1,3 +1,5 @@
+import { DateType } from "react-native-ui-datepicker";
+
 /**
  * Trasforma una data da "YYYY-MM-DD" a "DD/MM/YYYY"
  * @param dateStr stringa data in formato ISO "YYYY-MM-DD"
@@ -19,3 +21,21 @@ export const formatTime = (timeStr: string | null | undefined): string => {
     const [hours, minutes] = timeStr.split(':');
     return `${hours}:${minutes}`;
 };
+
+/**
+ * Formatta una data per l'uso con un date picker, normalizzandola a mezzanotte
+ * @param d Data in formato DateType
+ * @returns stringa data in formato "YYYY-MM-DD" o null se l'input è null/undefined
+ */
+export const formatPickerDate = (d: DateType | null | undefined) => {
+    if (!d) return null;
+
+    const date = new Date(d as string | number | Date);
+    const normalized = new Date(date.getFullYear(), date.getMonth(), date.getDate());
+
+    const yyyy = normalized.getFullYear();
+    const mm = String(normalized.getMonth() + 1).padStart(2, "0");
+    const dd = String(normalized.getDate()).padStart(2, "0");
+
+    return `${yyyy}-${mm}-${dd}`;
+}