second commit

lib/core/utils/extensions.dart

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+import 'package:flutter/material.dart';
+
+import '../theme/app_dimens.dart';
+
+extension BuildContextX on BuildContext {
+  ThemeData get theme => Theme.of(this);
+  TextTheme get text => Theme.of(this).textTheme;
+  ColorScheme get colors => Theme.of(this).colorScheme;
+
+  Size get screen => MediaQuery.sizeOf(this);
+  double get screenWidth => MediaQuery.sizeOf(this).width;
+  double get screenHeight => MediaQuery.sizeOf(this).height;
+
+  bool get isCompact => AppBreakpoints.isCompact(screenWidth);
+  bool get isMedium => AppBreakpoints.isMedium(screenWidth);
+  bool get isExpanded => AppBreakpoints.isExpanded(screenWidth);
+
+  /// Picks a value appropriate to the current breakpoint.
+  T responsive<T>({required T compact, T? medium, required T expanded}) {
+    if (isCompact) return compact;
+    if (isExpanded) return expanded;
+    return medium ?? expanded;
+  }
+
+  void showSnack(String message, {Color? background}) {
+    ScaffoldMessenger.of(this)
+      ..hideCurrentSnackBar()
+      ..showSnackBar(SnackBar(
+        content: Text(message),
+        backgroundColor: background,
+        duration: const Duration(seconds: 2),
+      ));
+  }
+}
+
+extension DoubleX on double {
+  /// Rounds to two decimals to avoid floating point drift in money maths.
+  double get asMoney => (this * 100).roundToDouble() / 100;
+
+  /// Indian retail round-off to the nearest rupee.
+  double get roundedToRupee => roundToDouble();
+}
+
+extension StringX on String {
+  String get capitalized =>
+      isEmpty ? this : '${this[0].toUpperCase()}${substring(1)}';
+
+  bool containsIgnoreCase(String other) =>
+      toLowerCase().contains(other.toLowerCase());
+}
+
+extension IterableX<T> on Iterable<T> {
+  T? firstWhereOrNull(bool Function(T) test) {
+    for (final element in this) {
+      if (test(element)) return element;
+    }
+    return null;
+  }
+}

lib/core/utils/formatters.dart

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+import 'package:intl/intl.dart';
+
+import '../constants/app_constants.dart';
+
+/// Currency, date and number formatting helpers.
+class Formatters {
+  const Formatters._();
+
+  static final NumberFormat _currency = NumberFormat.currency(
+    locale: AppConstants.locale,
+    symbol: AppConstants.currencySymbol,
+    decimalDigits: 2,
+  );
+
+  static final NumberFormat _compactCurrency = NumberFormat.compactCurrency(
+    locale: AppConstants.locale,
+    symbol: AppConstants.currencySymbol,
+    decimalDigits: 1,
+  );
+
+  static final DateFormat _time = DateFormat('hh:mm a');
+  static final DateFormat _date = DateFormat('dd MMM yyyy');
+  static final DateFormat _dateTime = DateFormat('dd MMM yyyy, hh:mm a');
+  static final DateFormat _receiptStamp = DateFormat('dd/MM/yyyy HH:mm:ss');
+
+  static String money(num value) => _currency.format(value);
+  static String moneyCompact(num value) => _compactCurrency.format(value);
+
+  /// Amount without the symbol — used where the symbol is styled separately.
+  static String amount(num value) => value.toStringAsFixed(2);
+
+  static String time(DateTime dt) => _time.format(dt);
+  static String date(DateTime dt) => _date.format(dt);
+  static String dateTime(DateTime dt) => _dateTime.format(dt);
+  static String receiptStamp(DateTime dt) => _receiptStamp.format(dt);
+
+  static String percent(double fraction) =>
+      '${(fraction * 100).toStringAsFixed(fraction * 100 % 1 == 0 ? 0 : 1)}%';
+
+  /// `9876543210` -> `98765 43210`
+  static String mobile(String raw) {
+    final digits = raw.replaceAll(RegExp(r'\D'), '');
+    if (digits.length != 10) return raw;
+    return '${digits.substring(0, 5)} ${digits.substring(5)}';
+  }
+
+  /// Masks all but the last four digits for on-screen privacy.
+  static String maskedMobile(String raw) {
+    final digits = raw.replaceAll(RegExp(r'\D'), '');
+    if (digits.length < 4) return raw;
+    return '${'\u2022' * (digits.length - 4)}${digits.substring(digits.length - 4)}';
+  }
+
+  static String initials(String name) {
+    final parts = name.trim().split(RegExp(r'\s+')).where((p) => p.isNotEmpty);
+    if (parts.isEmpty) return '?';
+    if (parts.length == 1) return parts.first.substring(0, 1).toUpperCase();
+    return (parts.first.substring(0, 1) + parts.last.substring(0, 1))
+        .toUpperCase();
+  }
+
+  static String invoiceNumber(int sequence, DateTime date) {
+    final y = date.year.toString().substring(2);
+    final m = date.month.toString().padLeft(2, '0');
+    return 'INV-$y$m-${sequence.toString().padLeft(5, '0')}';
+  }
+}

lib/core/utils/validators.dart

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+import '../constants/app_constants.dart';
+
+/// Form field validators returning a message, or null when valid.
+class Validators {
+  const Validators._();
+
+  static final RegExp _emailRe =
+      RegExp(r'^[\w.+-]+@([\w-]+\.)+[A-Za-z]{2,}$');
+  static final RegExp _mobileRe = RegExp(r'^[6-9]\d{9}$');
+
+  static String? mobile(String? value) {
+    final v = (value ?? '').replaceAll(RegExp(r'\D'), '');
+    if (v.isEmpty) return 'Mobile number is required';
+    if (v.length != AppConstants.mobileNumberLength) {
+      return 'Enter all ${AppConstants.mobileNumberLength} digits';
+    }
+    if (!_mobileRe.hasMatch(v)) return 'Enter a valid Indian mobile number';
+    return null;
+  }
+
+  static String? name(String? value) {
+    final v = (value ?? '').trim();
+    if (v.isEmpty) return 'Customer name is required';
+    if (v.length < 2) return 'Name is too short';
+    if (v.length > 60) return 'Name is too long';
+    return null;
+  }
+
+  static String? emailOptional(String? value) {
+    final v = (value ?? '').trim();
+    if (v.isEmpty) return null;
+    if (!_emailRe.hasMatch(v)) return 'Enter a valid email address';
+    return null;
+  }
+
+  static String? dobOptional(DateTime? value) {
+    if (value == null) return null;
+    final now = DateTime.now();
+    if (value.isAfter(now)) return 'Date of birth cannot be in the future';
+    if (now.year - value.year > 120) return 'Enter a valid date of birth';
+    return null;
+  }
+
+  static String? positiveAmount(String? value) {
+    final v = double.tryParse((value ?? '').trim());
+    if (v == null) return 'Enter a valid amount';
+    if (v <= 0) return 'Amount must be greater than zero';
+    return null;
+  }
+
+  static bool isLikelyBarcode(String value) {
+    final v = value.trim();
+    return v.length >= AppConstants.minBarcodeLength &&
+        RegExp(r'^\d+$').hasMatch(v);
+  }
+}