Fix billing data integrity, sale atomicity and stock safety

Bills were persisted correctly but read back wrong. The read path rebuilt a
cart from its lines alone, dropping bill-level discounts and loyalty, so every
figure derived from a stored bill was overstated: the upload payload, the day
archive and the shift report. A discounted 529 bill read back as 620.

Money and data integrity
- order_dao: restore bill_discount and points_redeemed when rebuilding a cart;
  keep the reconstruction tier-less so the membership discount is not applied
  twice. Trust the recorded total and points via SaleTransaction.storedTotal.
- checkout_sale + order_dao.commitSale: write the bill, its stock movement and
  the loyalty update in one transaction. Previously a failure part-way through
  left a persisted bill the cashier believed had failed, inviting a duplicate.
- checkout_sale: re-check every line against live stock. A parked bill resumed
  after its stock was sold passed validation and oversold.
- catalogue_dao: allocate the invoice sequence in one transaction; the previous
  read-modify-write could hand two sales the same number and fail UNIQUE.
- local_store: replay unsynced sales after a catalogue import, so a mid-shift
  re-import cannot restore stock that has already been sold.
- payment_controller: stamp the signed-in operator on the bill instead of the
  hardcoded seed session, and pass the terminal id through.
- cart: reconcile per-slab GST against the bill total so the parts sum to the
  whole on a tax invoice.

Sync and reporting
- sync_repository: drain unsynced bills in a loop rather than silently capping
  at one page; stop on rejection so rejected rows cannot loop forever.
- sync_log_dao (new): persist the sync history to the sync_log table, which the
  schema already defined but nothing used. It was in memory, so the only record
  that bills had been uploaded died at restart.
- Scope shift reports by cashier. day_archive is re-keyed to
  (business_date, cashier_name) so a till stays settleable after its bills are
  uploaded and deleted. Schema v4 with a migration that carries v3 rows across.

Input and UI
- barcode_service: consume machine-paced keystrokes so a scan cannot also land
  in the focused field, and raise the bar to 60ms/char while a text field has
  focus so typing a mobile number is not read as a scan. Clock and focus check
  injected so the behaviour is testable.
- primary_button: make the label flexible; label plus trailing total overflowed
  the Charge button by up to 131px.
- app_router: redirect instead of null-casting when the receipt route is
  entered without its transaction.
- customer_repository: reduce the search query to digits so a punctuated mobile
  number matches.

Cleanup
- Remove TransactionRepository.save, CustomerRepository.recordSale and
  OrderDao.insertOrder, all superseded by commitSale.
- dart fix across the tree; 251 analyzer issues down to 3 info-level.

Tests: 23 passing / 15 failing -> 90 passing. Fixed the two defects that broke
the existing suite (containsAll type argument, reset() needing a catalogue) and
deleted the leftover template test. Added coverage for the order round trip,
the day archive after a real sync, stock safety, checkout atomicity, the v3->v4
migration, scanner-versus-human input, and an app-level smoke test that renders
every module.

Note: bills already uploaded with a discount went up overstated. This stops it
happening again but does not correct historical server data.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

test/widget/app_smoke_test.dart

@@ -0,0 +1,130 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:google_fonts/google_fonts.dart';
+import 'package:nearle_pos/app/app.dart';
+import 'package:nearle_pos/data/datasources/local_store.dart';
+import 'package:nearle_pos/data/datasources/seed_data.dart';
+import 'package:nearle_pos/domain/entities/shift_report.dart';
+import 'package:nearle_pos/presentation/auth/providers/auth_controller.dart';
+import 'package:nearle_pos/presentation/pos/providers/cart_controller.dart';
+import 'package:nearle_pos/presentation/pos/screens/pos_dashboard_screen.dart';
+import 'package:nearle_pos/presentation/sync/providers/sync_controller.dart';
+
+/// Boots the real application widget.
+///
+/// The unit suite proves the money is right; this proves the thing actually
+/// assembles — router guard, provider graph, theme and shell — which type
+/// checking alone cannot tell you.
+void main() {
+  setUpAll(() {
+    // Tests have no network, and an attempted font fetch throws.
+    GoogleFonts.config.allowRuntimeFetching = false;
+    LocalStore.registerSeed(
+      products: SeedData.products,
+      customers: SeedData.customers,
+    );
+  });
+
+  setUp(() async {
+    await LocalStore.instance.reset(withCatalogue: true);
+  });
+
+  ShiftReport blankReport() => ShiftReport.blank(
+        businessDate: DateTime(2026, 7, 31),
+        terminalId: 'TERM-01',
+        cashierName: 'Suriya',
+      );
+
+  Future<void> bootApp(WidgetTester tester) async {
+    await tester.pumpWidget(
+      ProviderScope(
+        overrides: [
+          // Catalogue reads come from the in-memory cache and resolve on the
+          // spot, but these four go to SQLite. Real disk I/O cannot be driven
+          // by the fake clock a widget test runs on: sqflite's own lock-warning
+          // timer is left pending and trips the binding's leak check. Stubbed
+          // so this test measures rendering, which is what it is for.
+          unsyncedCountProvider.overrideWith((ref) async => 0),
+          parkedBillsProvider.overrideWith((ref) async => []),
+          orderSyncRowsProvider.overrideWith((ref) async => []),
+          todayReportProvider.overrideWith((ref) async => blankReport()),
+          myShiftReportProvider.overrideWith((ref) async => blankReport()),
+        ],
+        child: const NearlePosApp(),
+      ),
+    );
+    await tester.pumpAndSettle();
+  }
+
+  /// Pumps a fixed number of frames instead of settling.
+  ///
+  /// Once past login the header subscribes to a periodic clock, so there is
+  /// always another frame pending and `pumpAndSettle` never returns.
+  Future<void> settle(WidgetTester tester, {int frames = 15}) async {
+    for (var i = 0; i < frames; i++) {
+      await tester.pump(const Duration(milliseconds: 100));
+    }
+  }
+
+  Future<void> signIn(WidgetTester tester) async {
+    final fields = find.byType(TextFormField);
+    await tester.enterText(fields.first, DemoCredentials.email);
+    await tester.enterText(fields.at(1), DemoCredentials.password);
+    await tester.pump();
+
+    await tester.tap(find.text('Sign in').last);
+    await settle(tester);
+  }
+
+  testWidgets('the terminal starts on the login screen', (tester) async {
+    await bootApp(tester);
+
+    expect(find.byType(TextFormField), findsWidgets);
+    expect(find.text('Sign in'), findsWidgets);
+    expect(tester.takeException(), isNull);
+  });
+
+  testWidgets('the auth guard keeps an unauthenticated terminal out',
+      (tester) async {
+    await bootApp(tester);
+
+    expect(find.byType(PosDashboardScreen), findsNothing);
+  });
+
+  testWidgets('signing in reaches the billing terminal', (tester) async {
+    await bootApp(tester);
+    await signIn(tester);
+
+    expect(find.byType(PosDashboardScreen), findsOneWidget);
+    expect(tester.takeException(), isNull);
+  });
+
+  testWidgets('the shell renders every module without throwing',
+      (tester) async {
+    // Wide enough that the sidebar shows labels and the bill stays docked —
+    // the layout where a button label and its total compete for width.
+    tester.view.physicalSize = const Size(1800, 1200);
+    tester.view.devicePixelRatio = 1;
+    addTearDown(tester.view.reset);
+
+    await bootApp(tester);
+    await signIn(tester);
+
+    for (final label in [
+      'Customers',
+      'Product Import',
+      'Promo',
+      'Events',
+      'Settings',
+      'POS',
+    ]) {
+      final target = find.text(label);
+      expect(target, findsWidgets, reason: 'no sidebar entry for "$label"');
+
+      await tester.tap(target.first);
+      await settle(tester);
+      expect(tester.takeException(), isNull, reason: 'opening "$label" threw');
+    }
+  });
+}

test/widget/primary_button_test.dart

@@ -58,7 +58,7 @@ void main() {
           label: 'CHARGE',
           onPressed: () {},
           trailing: const Text('\u20B9384.00'),
-        )),
+        ),),
       );
 
       expect(find.text('CHARGE'), findsOneWidget);