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>

lib/core/router/app_router.dart

@@ -68,6 +68,11 @@ final routerProvider = Provider<GoRouter>((ref) {
       GoRoute(
         path: AppRoutes.receipt,
         name: 'receipt',
+        // The bill travels in `extra`, which does not survive a reload, a deep
+        // link or a restored session. Sending the cashier back to billing beats
+        // crashing on a null cast.
+        redirect: (context, state) =>
+            state.extra is SaleTransaction ? null : AppRoutes.pos,
         pageBuilder: (context, state) => _fade(
           state,
           ReceiptScreen(transaction: state.extra! as SaleTransaction),

lib/core/services/barcode_service.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 
 import 'package:flutter/services.dart';
+import 'package:flutter/widgets.dart';
 
 import '../constants/app_constants.dart';
 
@@ -11,17 +12,39 @@ import '../constants/app_constants.dart';
 /// when the characters arrived faster than a human could type — that way the
 /// cashier can still type into the same field by hand.
 class BarcodeService {
-  BarcodeService({this.onScan, this.onManualKey});
+  BarcodeService({
+    this.onScan,
+    this.onManualKey,
+    DateTime Function()? clock,
+    bool Function()? isEditingText,
+  })  : _clock = clock ?? DateTime.now,
+        _isEditingText = isEditingText ?? _primaryFocusIsTextField;
 
   final void Function(String code)? onScan;
   final VoidCallback? onManualKey;
 
+  /// Injectable so tests can drive keystroke timing exactly rather than
+  /// sleeping, which is what makes scanner-versus-human behaviour testable.
+  final DateTime Function() _clock;
+  final bool Function() _isEditingText;
+
   final StringBuffer _buffer = StringBuffer();
   DateTime? _lastKeyAt;
+  DateTime? _firstKeyAt;
+  int _charCount = 0;
+
+  /// Cleared when any gap in the buffer is too slow to be a machine.
+  bool _machinePaced = true;
+
   Timer? _flushTimer;
 
   bool _attached = false;
 
+  /// Sustained pace no typist holds. Applied when a text field has focus, where
+  /// the cost of a false positive is a swallowed keystroke rather than nothing.
+  static Duration get _strictGap =>
+      Duration(microseconds: AppConstants.barcodeScanTimeout.inMicroseconds ~/ 2);
+
   void attach() {
     if (_attached) return;
     HardwareKeyboard.instance.addHandler(_handleKey);
@@ -35,22 +58,44 @@ class BarcodeService {
     _attached = false;
   }
 
+  /// Whether the cashier is typing into a field right now.
+  ///
+  /// A scan still registers while a field has focus, but the bar for calling it
+  /// a scan is raised, because getting it wrong means eating real keystrokes.
+  static bool _primaryFocusIsTextField() {
+    final context = FocusManager.instance.primaryFocus?.context;
+    if (context == null) return false;
+    return context.widget is EditableText ||
+        context.findAncestorWidgetOfExactType<EditableText>() != null;
+  }
+
+  void _resetBuffer() {
+    _buffer.clear();
+    _firstKeyAt = null;
+    _charCount = 0;
+    _machinePaced = true;
+  }
+
+  /// The key handler, exposed so it can be driven directly in tests.
+  @visibleForTesting
+  bool handleKey(KeyEvent event) => _handleKey(event);
+
   bool _handleKey(KeyEvent event) {
     if (event is! KeyDownEvent) return false;
 
-    final now = DateTime.now();
+    final now = _clock();
-    final gap = _lastKeyAt == null
+    final gap = _lastKeyAt == null ? Duration.zero : now.difference(_lastKeyAt!);
-        ? Duration.zero
-        : now.difference(_lastKeyAt!);
     _lastKeyAt = now;
 
     // A long pause means a new entry started; discard whatever was buffered.
     if (gap > AppConstants.barcodeScanTimeout) {
-      _buffer.clear();
+      _resetBuffer();
     }
 
     if (event.logicalKey == LogicalKeyboardKey.enter ||
         event.logicalKey == LogicalKeyboardKey.numpadEnter) {
+      // Only swallow Enter if the buffer actually resolves to a scan —
+      // otherwise a form submit on a hand-typed field would be eaten.
       return _flush();
     }
 
@@ -58,9 +103,19 @@ class BarcodeService {
     if (char == null || char.trim().isEmpty) return false;
     if (!RegExp(r'^[0-9A-Za-z\-]$').hasMatch(char)) return false;
 
+    if (_charCount > 0 && gap > AppConstants.barcodeScanTimeout) {
+      _machinePaced = false;
+    }
+
     _buffer.write(char);
+    _firstKeyAt ??= now;
+    _charCount++;
     _scheduleFlush();
-    return false;
+
+    // Consume the keystroke once the burst is unmistakably machine-paced.
+    // Without this the scanned digits also land in whatever field has focus,
+    // so a scan would add the item *and* type the barcode into the search box.
+    return _looksLikeScan(atLeast: 2);
   }
 
   /// Some scanners are not configured to send a terminating Enter, so we also
@@ -69,16 +124,31 @@ class BarcodeService {
     _flushTimer?.cancel();
     _flushTimer = Timer(
       AppConstants.barcodeScanTimeout * 2,
-      () => _flush(),
+      _flush,
     );
   }
 
+  /// Whether the buffer so far has the shape and speed of a scanner burst.
+  bool _looksLikeScan({required int atLeast}) {
+    if (_charCount < atLeast || !_machinePaced) return false;
+
+    final first = _firstKeyAt;
+    if (first == null || _charCount < 2) return false;
+
+    final span = _lastKeyAt!.difference(first);
+    final averageGap = span ~/ (_charCount - 1);
+
+    return averageGap <=
+        (_isEditingText() ? _strictGap : AppConstants.barcodeScanTimeout);
+  }
+
   bool _flush() {
     _flushTimer?.cancel();
     final code = _buffer.toString().trim();
-    _buffer.clear();
+    final wasScan = _looksLikeScan(atLeast: AppConstants.minBarcodeLength);
+    _resetBuffer();
 
-    if (code.length >= AppConstants.minBarcodeLength) {
+    if (wasScan && code.length >= AppConstants.minBarcodeLength) {
       onScan?.call(code);
       return true;
     }

lib/core/services/receipt_service.dart

@@ -1,4 +1,3 @@
-import 'dart:typed_data';
 
 import 'package:flutter/foundation.dart';
 import 'package:pdf/pdf.dart';
@@ -58,7 +57,7 @@ class ReceiptService {
 
     doc.addPage(
       pw.Page(
-        pageFormat: PdfPageFormat(
+        pageFormat: const PdfPageFormat(
           _rollWidth,
           double.infinity,
           marginAll: 5 * PdfPageFormat.mm,
@@ -94,23 +93,23 @@ class ReceiptService {
   pw.Widget _header(SaleTransaction txn) => pw.Column(children: [
         pw.Text(
           AppConstants.storeName.toUpperCase(),
-          style: pw.TextStyle(fontSize: 15, fontWeight: pw.FontWeight.bold),
+          style: const pw.TextStyle(fontSize: 15, fontWeight: pw.FontWeight.bold),
         ),
         pw.Text(AppConstants.storeLegalName,
-            style: const pw.TextStyle(fontSize: 7)),
+            style: const pw.TextStyle(fontSize: 7),),
         pw.SizedBox(height: 2),
         pw.Text(AppConstants.storeAddress,
             style: const pw.TextStyle(fontSize: 6.5),
-            textAlign: pw.TextAlign.center),
+            textAlign: pw.TextAlign.center,),
         pw.Text('Customer care : ${AppConstants.storePhone}',
-            style: const pw.TextStyle(fontSize: 6.5)),
+            style: const pw.TextStyle(fontSize: 6.5),),
         pw.Text('CIN No : ${AppConstants.storeCin}',
-            style: const pw.TextStyle(fontSize: 6.5)),
+            style: const pw.TextStyle(fontSize: 6.5),),
         pw.Text('GSTIN : ${AppConstants.storeGstin}',
-            style: const pw.TextStyle(fontSize: 6.5)),
+            style: const pw.TextStyle(fontSize: 6.5),),
         pw.Text('FSSAI Lic No : ${AppConstants.storeFssai}',
-            style: const pw.TextStyle(fontSize: 6.5)),
+            style: const pw.TextStyle(fontSize: 6.5),),
-      ]);
+      ],);
 
   pw.Widget _savingsLine(SaleTransaction txn) {
     final saved = _grossSalesValue(txn) - txn.cart.netAmount;
@@ -120,7 +119,7 @@ class ReceiptService {
       padding: const pw.EdgeInsets.symmetric(vertical: 4),
       child: pw.Text(
         'You have saved Rs.${saved.toStringAsFixed(2)}',
-        style: pw.TextStyle(fontSize: 9, fontWeight: pw.FontWeight.bold),
+        style: const pw.TextStyle(fontSize: 9, fontWeight: pw.FontWeight.bold),
         textAlign: pw.TextAlign.center,
       ),
     );
@@ -128,11 +127,11 @@ class ReceiptService {
 
   pw.Widget _invoiceTitle() => pw.Column(children: [
         pw.Text('TAX INVOICE',
-            style: pw.TextStyle(fontSize: 9, fontWeight: pw.FontWeight.bold)),
+            style: const pw.TextStyle(fontSize: 9, fontWeight: pw.FontWeight.bold),),
         pw.SizedBox(height: 1),
         pw.Text('xxxxxx Original for Recipient xxxxxx',
-            style: const pw.TextStyle(fontSize: 6)),
+            style: const pw.TextStyle(fontSize: 6),),
-      ]);
+      ],);
 
   pw.Widget _meta(SaleTransaction txn) {
     final c = txn.customer;
@@ -167,7 +166,7 @@ class ReceiptService {
           pw.Expanded(flex: 16, child: _th('Net Price', right: true)),
           pw.Expanded(flex: 8, child: _th('Qty', right: true)),
           pw.Expanded(flex: 18, child: _th('Value', right: true)),
-        ]),
+        ],),
         pw.SizedBox(height: 2),
         for (final slab in slabs) ...[
           pw.Padding(
@@ -175,7 +174,7 @@ class ReceiptService {
             child: pw.Text(
               '${slab.index}) CGST @ ${slab.halfPercent}  '
               'SGST @ ${slab.halfPercent}',
-              style: pw.TextStyle(fontSize: 7, fontWeight: pw.FontWeight.bold),
+              style: const pw.TextStyle(fontSize: 7, fontWeight: pw.FontWeight.bold),
             ),
           ),
           for (final line in slab.lines)
@@ -193,7 +192,7 @@ class ReceiptService {
                 pw.Expanded(
                   flex: 16,
                   child: _td(line.product.price.toStringAsFixed(2),
-                      right: true, size: 6.5),
+                      right: true, size: 6.5,),
                 ),
                 pw.Expanded(
                   flex: 8,
@@ -202,9 +201,9 @@ class ReceiptService {
                 pw.Expanded(
                   flex: 18,
                   child: _td(line.payable.toStringAsFixed(2),
-                      right: true, size: 6.5),
+                      right: true, size: 6.5,),
                 ),
-              ]),
+              ],),
             ),
         ],
       ],
@@ -237,14 +236,14 @@ class ReceiptService {
       if (txn.changeDue > 0) _amount('Change Returned', txn.changeDue),
       pw.SizedBox(height: 1),
       pw.Text('(AMOUNT INCLUSIVE OF APPLICABLE TAXES)',
-          style: const pw.TextStyle(fontSize: 6)),
+          style: const pw.TextStyle(fontSize: 6),),
-    ]);
+    ],);
   }
 
   pw.Widget _gstBreakup(SaleTransaction txn, List<_Slab> slabs) {
     return pw.Column(children: [
       pw.Text('------GST Breakup Details------ Amount (INR)',
-          style: const pw.TextStyle(fontSize: 6.5)),
+          style: const pw.TextStyle(fontSize: 6.5),),
       pw.SizedBox(height: 3),
       pw.Row(children: [
         pw.Expanded(flex: 10, child: _th('GST\nIND', size: 6)),
@@ -253,7 +252,7 @@ class ReceiptService {
         pw.Expanded(flex: 16, child: _th('SGST', right: true, size: 6)),
         pw.Expanded(flex: 14, child: _th('CESS', right: true, size: 6)),
         pw.Expanded(flex: 20, child: _th('Total\nAmount', right: true, size: 6)),
-      ]),
+      ],),
       pw.SizedBox(height: 2),
       for (final s in slabs)
         pw.Padding(
@@ -263,19 +262,19 @@ class ReceiptService {
             pw.Expanded(
                 flex: 20,
                 child: _td(s.taxable.toStringAsFixed(2),
-                    right: true, size: 6.5)),
+                    right: true, size: 6.5,),),
             pw.Expanded(
                 flex: 16,
-                child: _td(s.cgst.toStringAsFixed(2), right: true, size: 6.5)),
+                child: _td(s.cgst.toStringAsFixed(2), right: true, size: 6.5),),
             pw.Expanded(
                 flex: 16,
-                child: _td(s.sgst.toStringAsFixed(2), right: true, size: 6.5)),
+                child: _td(s.sgst.toStringAsFixed(2), right: true, size: 6.5),),
             pw.Expanded(flex: 14, child: _td('0.00', right: true, size: 6.5)),
             pw.Expanded(
                 flex: 20,
                 child:
-                    _td(s.total.toStringAsFixed(2), right: true, size: 6.5)),
+                    _td(s.total.toStringAsFixed(2), right: true, size: 6.5),),
-          ]),
+          ],),
         ),
       pw.Divider(height: 4, borderStyle: pw.BorderStyle.dashed),
       pw.Row(children: [
@@ -285,24 +284,24 @@ class ReceiptService {
             child: _th(
                 slabs.fold(0.0, (a, s) => a + s.taxable).toStringAsFixed(2),
                 right: true,
-                size: 6.5)),
+                size: 6.5,),),
         pw.Expanded(
             flex: 16,
             child: _th(slabs.fold(0.0, (a, s) => a + s.cgst).toStringAsFixed(2),
-                right: true, size: 6.5)),
+                right: true, size: 6.5,),),
         pw.Expanded(
             flex: 16,
             child: _th(slabs.fold(0.0, (a, s) => a + s.sgst).toStringAsFixed(2),
-                right: true, size: 6.5)),
+                right: true, size: 6.5,),),
         pw.Expanded(flex: 14, child: _th('0.00', right: true, size: 6.5)),
         pw.Expanded(
             flex: 20,
             child: _th(
                 slabs.fold(0.0, (a, s) => a + s.total).toStringAsFixed(2),
                 right: true,
-                size: 6.5)),
+                size: 6.5,),),
-      ]),
+      ],),
-    ]);
+    ],);
   }
 
   pw.Widget _references(SaleTransaction txn) {
@@ -341,14 +340,14 @@ class ReceiptService {
         ),
         pw.SizedBox(height: 3),
         pw.Text('* Thank You for Shopping with us *',
-            style: pw.TextStyle(fontSize: 7, fontWeight: pw.FontWeight.bold)),
+            style: const pw.TextStyle(fontSize: 7, fontWeight: pw.FontWeight.bold),),
         pw.Text('Goods once sold are exchangeable within 7 days with this bill',
             style: const pw.TextStyle(fontSize: 5.5),
-            textAlign: pw.TextAlign.center),
+            textAlign: pw.TextAlign.center,),
         pw.SizedBox(height: 2),
         pw.Text('Powered by Nearle POS',
-            style: const pw.TextStyle(fontSize: 5.5)),
+            style: const pw.TextStyle(fontSize: 5.5),),
-      ]);
+      ],);
 
   // -------------------------------------------------------------- Helpers
   /// Pre-discount value, using printed MRP where one is known.
@@ -391,12 +390,12 @@ class ReceiptService {
                 style: pw.TextStyle(
                   fontSize: 6.8,
                   fontWeight: bold ? pw.FontWeight.bold : pw.FontWeight.normal,
-                )),
+                ),),
             pw.Text(value.toStringAsFixed(2),
                 style: pw.TextStyle(
                   fontSize: 6.8,
                   fontWeight: bold ? pw.FontWeight.bold : pw.FontWeight.normal,
-                )),
+                ),),
           ],
         ),
       );
@@ -404,14 +403,14 @@ class ReceiptService {
   pw.Widget _th(String text, {bool right = false, double size = 6.8}) =>
       pw.Text(text,
           textAlign: right ? pw.TextAlign.right : pw.TextAlign.left,
-          style: pw.TextStyle(fontSize: size, fontWeight: pw.FontWeight.bold));
+          style: pw.TextStyle(fontSize: size, fontWeight: pw.FontWeight.bold),);
 
   pw.Widget _td(String text, {bool right = false, double size = 6.8}) =>
       pw.Text(text,
           maxLines: 1,
           overflow: pw.TextOverflow.clip,
           textAlign: right ? pw.TextAlign.right : pw.TextAlign.left,
-          style: pw.TextStyle(fontSize: size));
+          style: pw.TextStyle(fontSize: size),);
 
   // --------------------------------------------------------- Printing / IO
   /// Opens the system print preview.
@@ -483,7 +482,7 @@ class ReceiptService {
       final font = await PdfGoogleFonts.robotoMonoRegular();
       doc.addPage(
         pw.Page(
-          pageFormat: PdfPageFormat(
+          pageFormat: const PdfPageFormat(
             _rollWidth,
             double.infinity,
             marginAll: 5 * PdfPageFormat.mm,
@@ -491,16 +490,16 @@ class ReceiptService {
           theme: pw.ThemeData.withFont(base: font),
           build: (_) => pw.Column(children: [
             pw.Text(AppConstants.storeName.toUpperCase(),
-                style: pw.TextStyle(fontSize: 14, fontWeight: pw.FontWeight.bold)),
+                style: const pw.TextStyle(fontSize: 14, fontWeight: pw.FontWeight.bold),),
             pw.SizedBox(height: 6),
             pw.Text('PRINTER TEST', style: const pw.TextStyle(fontSize: 10)),
             pw.SizedBox(height: 4),
             pw.Text(target.name, style: const pw.TextStyle(fontSize: 7)),
             pw.Text(Formatters.dateTime(DateTime.now()),
-                style: const pw.TextStyle(fontSize: 7)),
+                style: const pw.TextStyle(fontSize: 7),),
             pw.SizedBox(height: 6),
             pw.Text('1234567890 ABCDEFGHIJ',
-                style: const pw.TextStyle(fontSize: 8)),
+                style: const pw.TextStyle(fontSize: 8),),
             pw.Text('₹ 1,234.56', style: const pw.TextStyle(fontSize: 8)),
             pw.SizedBox(height: 6),
             pw.BarcodeWidget(
@@ -510,7 +509,7 @@ class ReceiptService {
               height: 30,
               drawText: false,
             ),
-          ]),
+          ],),
         ),
       );
 

lib/core/theme/app_theme.dart

@@ -40,13 +40,13 @@ class AppTheme {
             ?.copyWith(color: AppColors.textOnPrimary),
       ),
 
-      cardTheme: CardThemeData(
+      cardTheme: const CardThemeData(
         color: AppColors.surface,
         elevation: 0,
         margin: EdgeInsets.zero,
         shape: RoundedRectangleBorder(
           borderRadius: AppRadius.brLg,
-          side: const BorderSide(color: AppColors.border),
+          side: BorderSide(color: AppColors.border),
         ),
       ),
 
@@ -149,7 +149,7 @@ class AppTheme {
         TargetPlatform.macOS: FadeUpwardsPageTransitionsBuilder(),
         TargetPlatform.linux: FadeUpwardsPageTransitionsBuilder(),
         TargetPlatform.android: FadeUpwardsPageTransitionsBuilder(),
-      }),
+      },),
     );
   }
 

lib/core/theme/app_typography.dart

@@ -31,12 +31,12 @@ class AppTypography {
       bodyLarge: _s(base.bodyLarge, 15.5, FontWeight.w400, 0),
       bodyMedium: _s(base.bodyMedium, 14.5, FontWeight.w400, 0),
       bodySmall: _s(base.bodySmall, 12.5, FontWeight.w400, 0,
-          color: AppColors.textSecondary),
+          color: AppColors.textSecondary,),
 
       labelLarge: _s(base.labelLarge, 14.5, FontWeight.w600, 0),
       labelMedium: _s(base.labelMedium, 12.5, FontWeight.w600, 0.1),
       labelSmall: _s(base.labelSmall, 10.5, FontWeight.w600, 0.6,
-          color: AppColors.textTertiary),
+          color: AppColors.textTertiary,),
     );
   }
 
@@ -58,7 +58,7 @@ class AppTypography {
 
   /// Tabular figures — essential so totals don't jitter as quantities change.
   static TextStyle money(double size,
-          {FontWeight weight = FontWeight.w700, Color? color}) =>
+          {FontWeight weight = FontWeight.w700, Color? color,}) =>
       GoogleFonts.poppins(
         fontSize: size,
         fontWeight: weight,

lib/core/utils/extensions.dart

@@ -29,7 +29,7 @@ extension BuildContextX on BuildContext {
         content: Text(message),
         backgroundColor: background,
         duration: const Duration(seconds: 2),
-      ));
+      ),);
   }
 }
 

lib/core/widgets/empty_state.dart

@@ -36,7 +36,7 @@ class EmptyState extends StatelessWidget {
               ),
               alignment: Alignment.center,
               child: Text(emoji,
-                  style: TextStyle(fontSize: compact ? 28 : 40)),
+                  style: TextStyle(fontSize: compact ? 28 : 40),),
             ),
             SizedBox(height: compact ? AppSpacing.lg : AppSpacing.xxl),
             Text(

lib/core/widgets/primary_button.dart

@@ -49,28 +49,36 @@ class PrimaryButton extends StatelessWidget {
                 ? MainAxisAlignment.spaceBetween
                 : MainAxisAlignment.center,
             children: [
-              Row(
+              // Flexible so the label gives way to the trailing total rather
-                mainAxisSize: MainAxisSize.min,
+              // than overflowing the button: on a narrow bill panel "Charge"
-                children: [
+              // plus a five-figure amount is wider than the button itself.
-                  if (icon != null) ...[
+              Flexible(
-                    Icon(icon, size: large ? 24 : 20, color: fg),
+                child: Row(
-                    const SizedBox(width: AppSpacing.sm),
+                  mainAxisSize: MainAxisSize.min,
-                  ],
+                  children: [
-                  Flexible(
+                    if (icon != null) ...[
-                    child: Text(
+                      Icon(icon, size: large ? 24 : 20, color: fg),
-                      label,
+                      const SizedBox(width: AppSpacing.sm),
-                      overflow: TextOverflow.ellipsis,
+                    ],
-                      style: TextStyle(
+                    Flexible(
-                        color: fg,
+                      child: Text(
-                        fontSize: large ? 19 : 16,
+                        label,
-                        fontWeight: FontWeight.w700,
+                        overflow: TextOverflow.ellipsis,
-                        letterSpacing: 0.1,
+                        style: TextStyle(
+                          color: fg,
+                          fontSize: large ? 19 : 16,
+                          fontWeight: FontWeight.w700,
+                          letterSpacing: 0.1,
+                        ),
                       ),
                     ),
-                  ),
+                  ],
-                ],
+                ),
               ),
-              if (trailing != null) trailing!,
+              if (trailing != null) ...[
+                const SizedBox(width: AppSpacing.sm),
+                trailing!,
+              ],
             ],
           );
 

lib/data/datasources/local_store.dart

@@ -1,8 +1,10 @@
 import '../../domain/entities/customer.dart';
 import '../../domain/entities/product.dart';
+import '../../domain/entities/sync_event.dart';
 import '../local/app_database.dart';
 import '../local/catalogue_dao.dart';
 import '../local/order_dao.dart';
+import '../local/sync_log_dao.dart';
 
 /// Terminal-side storage facade.
 ///
@@ -17,9 +19,11 @@ class LocalStore {
 
   late CatalogueDao catalogue;
   late OrderDao orders;
+  late SyncLogDao syncLog;
 
   final Map<String, Product> _products = {};
   final Map<String, Customer> _customers = {};
+  final List<SyncEvent> _syncEvents = [];
 
   DateTime? _lastImportAt;
   String? _catalogueRevision;
@@ -39,6 +43,7 @@ class LocalStore {
 
     catalogue = CatalogueDao(AppDatabase.instance.db);
     orders = OrderDao(AppDatabase.instance.db);
+    syncLog = SyncLogDao(AppDatabase.instance.db);
 
     await hydrate();
     _ready = true;
@@ -63,6 +68,20 @@ class LocalStore {
         : DateTime.fromMillisecondsSinceEpoch(int.parse(stamp));
     _catalogueRevision = await catalogue.meta(MetaKeys.catalogueRevision);
     _unsyncedOrders = await orders.unsyncedCount();
+
+    _syncEvents
+      ..clear()
+      ..addAll(await syncLog.recent());
+  }
+
+  // ---------------------------------------------------------------- Sync log
+  /// Newest first. Backed by the table, so it survives a restart.
+  List<SyncEvent> get syncEvents => List.unmodifiable(_syncEvents);
+
+  Future<void> appendSyncEvent(SyncEvent event) async {
+    await syncLog.insert(event);
+    await syncLog.trim();
+    _syncEvents.insert(0, event);
   }
 
   /// Test helper: wipes every table and reloads.
@@ -102,6 +121,15 @@ class LocalStore {
     required DateTime at,
   }) async {
     await catalogue.replaceCatalogue(products: products, customers: customers);
+
+    // The server's stock figure predates any sale this terminal has made but
+    // not yet uploaded, so those units would reappear on the shelf. Replay them
+    // before anyone can bill against the inflated count.
+    final committed = await orders.unsyncedStockCommitments();
+    if (committed.isNotEmpty) {
+      await catalogue.decrementStock(committed);
+    }
+
     await catalogue.setMeta(
       MetaKeys.lastImportAt,
       '${at.millisecondsSinceEpoch}',
@@ -131,6 +159,12 @@ class LocalStore {
 
   Future<void> applyStockMovement(Map<String, double> quantities) async {
     await catalogue.decrementStock(quantities);
+    cacheStockMovement(quantities);
+  }
+
+  /// Mirrors a stock decrement already written to disk into the memory cache.
+  /// Used after a sale is committed as part of a larger transaction.
+  void cacheStockMovement(Map<String, double> quantities) {
     quantities.forEach((id, qty) {
       final p = _products[id];
       if (p == null) return;
@@ -149,6 +183,9 @@ class LocalStore {
     _customers[c.id] = c;
   }
 
+  /// Mirrors a customer already written to disk into the memory cache.
+  void cacheCustomer(Customer c) => _customers[c.id] = c;
+
   // ----------------------------------------------------------------- Orders
   /// Refreshes the cached unsynced tally after a write or a sync.
   Future<int> refreshUnsyncedCount() async {

lib/data/local/app_database.dart

@@ -1,6 +1,5 @@
 import 'package:flutter/foundation.dart';
 import 'package:path/path.dart' as p;
-import 'package:sqflite/sqflite.dart';
 import 'package:sqflite_common_ffi/sqflite_ffi.dart';
 
 /// SQLite database for the terminal.
@@ -14,7 +13,7 @@ class AppDatabase {
   static final AppDatabase instance = AppDatabase._();
 
   static const String _fileName = 'nearle_pos.db';
-  static const int _version = 3;
+  static const int _version = 4;
 
   Database? _db;
 
@@ -70,6 +69,7 @@ class AppDatabase {
               'ALTER TABLE ${Tables.products} ADD COLUMN hsn_code TEXT',
             );
           }
+          if (from < 4) await _upgradeToV4(db, from: from);
         },
       ),
     );
@@ -238,18 +238,7 @@ class AppDatabase {
     ''');
 
     // -------------------------------------------------------------- syncLog
-    await db.execute('''
+    await db.execute(_createSyncLog);
-      CREATE TABLE ${Tables.syncLog} (
-        id          TEXT PRIMARY KEY,
-        type        TEXT    NOT NULL,
-        status      TEXT    NOT NULL,
-        created_at  INTEGER NOT NULL,
-        synced_at   INTEGER,
-        summary     TEXT    NOT NULL,
-        error       TEXT,
-        attempts    INTEGER NOT NULL DEFAULT 0
-      )
-    ''');
 
     // ------------------------------------------------------------- archive
     await db.execute(_createDayArchive);
@@ -264,14 +253,61 @@ class AppDatabase {
   }
 }
 
-/// Running totals per business day.
+/// Moves the schema to v4.
+///
+/// Adds the payload column the sync log needs to be usable at all, and re-keys
+/// the day archive by cashier so a shift report can be scoped to whoever is
+/// settling their till. Existing archived rows predate per-cashier attribution,
+/// so they are folded under an empty name rather than guessed at.
+Future<void> _upgradeToV4(Database db, {required int from}) async {
+  // A v1 database had no sync_log payload column; v2+ did not either.
+  await db.execute(
+    'ALTER TABLE ${Tables.syncLog} ADD COLUMN payload_json TEXT',
+  );
+
+  await db.execute('ALTER TABLE ${Tables.dayArchive} RENAME TO _day_archive_v3');
+  await db.execute(_createDayArchive);
+  await db.execute('''
+    INSERT INTO ${Tables.dayArchive} (
+      business_date, cashier_name, bill_count, item_count, gross_sales,
+      tax_collected, discount_given, round_off, points_issued,
+      points_redeemed, payments_json, first_bill_at, last_bill_at,
+      synced_bills
+    )
+    SELECT
+      business_date, '', bill_count, item_count, gross_sales,
+      tax_collected, discount_given, round_off, points_issued,
+      points_redeemed, payments_json, first_bill_at, last_bill_at,
+      synced_bills
+    FROM _day_archive_v3
+  ''');
+  await db.execute('DROP TABLE _day_archive_v3');
+}
+
+const String _createSyncLog = '''
+  CREATE TABLE sync_log (
+    id           TEXT PRIMARY KEY,
+    type         TEXT    NOT NULL,
+    status       TEXT    NOT NULL,
+    created_at   INTEGER NOT NULL,
+    synced_at    INTEGER,
+    summary      TEXT    NOT NULL,
+    error        TEXT,
+    attempts     INTEGER NOT NULL DEFAULT 0,
+    payload_json TEXT
+  )
+''';
+
+/// Running totals per business day and cashier.
 ///
 /// Synced orders are deleted from the terminal, so their figures are folded in
 /// here first — otherwise "Bills Today" would collapse to zero the moment a
-/// mid-shift sync ran.
+/// mid-shift sync ran. Keyed by cashier as well as date, because once the
+/// orders are gone this row is the only thing left to settle a till against.
 const String _createDayArchive = '''
   CREATE TABLE day_archive (
-    business_date   TEXT PRIMARY KEY,
+    business_date   TEXT    NOT NULL,
+    cashier_name    TEXT    NOT NULL DEFAULT '',
     bill_count      INTEGER NOT NULL DEFAULT 0,
     item_count      REAL    NOT NULL DEFAULT 0,
     gross_sales     REAL    NOT NULL DEFAULT 0,
@@ -283,7 +319,8 @@ const String _createDayArchive = '''
     payments_json   TEXT    NOT NULL DEFAULT '{}',
     first_bill_at   INTEGER,
     last_bill_at    INTEGER,
-    synced_bills    INTEGER NOT NULL DEFAULT 0
+    synced_bills    INTEGER NOT NULL DEFAULT 0,
+    PRIMARY KEY (business_date, cashier_name)
   )
 ''';
 

lib/data/local/catalogue_dao.dart

@@ -78,7 +78,7 @@ class CatalogueDao {
 
   static DateTime? _date(Object? millis) => millis == null
       ? null
-      : DateTime.fromMillisecondsSinceEpoch(millis! as int);
+      : DateTime.fromMillisecondsSinceEpoch(millis as int);
 
   // -------------------------------------------------------------- Products
   Future<List<Product>> allProducts() async {
@@ -248,10 +248,30 @@ class CatalogueDao {
   }
 
   /// Monotonic invoice counter held in the meta table.
+  ///
+  /// Read and write happen in one transaction. Done as separate awaits, two
+  /// checkouts could interleave, take the same number, and the second insert
+  /// would then fail the UNIQUE constraint on `invoice_number` — after the
+  /// sequence had already been consumed.
   Future<int> nextInvoiceSequence() async {
-    final current = int.tryParse(await meta(MetaKeys.invoiceSequence) ?? '0') ?? 0;
+    return _db.transaction<int>((txn) async {
-    final next = current + 1;
+      final rows = await txn.query(
-    await setMeta(MetaKeys.invoiceSequence, '$next');
+        Tables.meta,
-    return next;
+        where: 'key = ?',
+        whereArgs: [MetaKeys.invoiceSequence],
+        limit: 1,
+      );
+      final current = rows.isEmpty
+          ? 0
+          : int.tryParse(rows.first['value']! as String) ?? 0;
+      final next = current + 1;
+
+      await txn.insert(
+        Tables.meta,
+        {'key': MetaKeys.invoiceSequence, 'value': '$next'},
+        conflictAlgorithm: ConflictAlgorithm.replace,
+      );
+      return next;
+    });
   }
 }

lib/data/local/order_dao.dart

@@ -28,76 +28,127 @@ class OrderDao {
       '${dt.day.toString().padLeft(2, '0')}';
 
   // ----------------------------------------------------------------- Write
-  /// Writes the bill and its lines atomically.
+  /// Commits an entire sale in one transaction.
-  Future<void> insertOrder(SaleTransaction t) async {
+  ///
-    final cart = t.cart;
+  /// The bill, the stock it consumed and the shopper's loyalty movement have to
-
+  /// land together or not at all. Applied as three separate writes, a failure
+  /// part-way through left a persisted bill with unapplied loyalty while the
+  /// cashier saw an error and rang the sale again — a duplicate bill and a
+  /// double stock decrement.
+  Future<void> commitSale({
+    required SaleTransaction transaction,
+    required Map<String, double> stockMovements,
+    Map<String, Object?>? customerRow,
+  }) async {
     await _db.transaction((txn) async {
-      await txn.insert(
+      await _insertOrder(txn, transaction);
-        Tables.orders,
-        {
-          'id': t.id,
-          'invoice_number': t.invoiceNumber,
-          'created_at': t.createdAt.millisecondsSinceEpoch,
-          'business_date': businessDateOf(t.createdAt),
-          'cashier_name': t.cashierName,
-          'terminal_id': t.terminalId,
-          'customer_id': cart.customer?.id,
-          'customer_mobile': cart.customer?.mobile,
-          'customer_name': cart.customer?.name,
-          'subtotal': cart.subtotal,
-          'line_discount': cart.lineDiscountTotal,
-          'bill_discount': cart.billDiscountTotal,
-          'loyalty_value': cart.loyaltyRedemptionValue,
-          'taxable_amount': cart.taxableAmount,
-          'tax_amount': cart.taxAmount,
-          'round_off': cart.roundOff,
-          'total': t.total,
-          'points_earned': cart.pointsEarned,
-          'points_redeemed': cart.pointsRedeemed,
-          'payments_json': jsonEncode([
-            for (final p in t.payments)
-              {
-                'method': p.method.name,
-                'amount': p.amount,
-                'tendered': p.tendered,
-                'reference': p.reference,
-              },
-          ]),
-          'status': t.status.name,
-          'sync_status': pending,
-          'sync_attempts': 0,
-        },
-        conflictAlgorithm: ConflictAlgorithm.replace,
-      );
 
       final batch = txn.batch();
-      for (final line in cart.lines) {
+      final now = DateTime.now().millisecondsSinceEpoch;
-        batch.insert(Tables.orderItems, {
+      stockMovements.forEach((id, qty) {
-          'order_id': t.id,
+        batch.rawUpdate(
-          'product_id': line.product.id,
+          'UPDATE ${Tables.products} '
-          'name': line.product.name,
+          'SET stock = MAX(0, stock - ?), updated_at = ? WHERE id = ?',
-          'barcode': line.product.barcode,
+          [qty, now, id],
-          'sku': line.product.sku,
+        );
-          'unit': line.product.unit.name,
+      });
-          'unit_price': line.product.price,
+      if (customerRow != null) {
-          'quantity': line.quantity,
+        batch.insert(
-          'discount': line.discountAmount,
+          Tables.customers,
-          'gst_rate': line.product.gstRate,
+          customerRow,
-          'tax_amount': line.taxAmount,
+          conflictAlgorithm: ConflictAlgorithm.replace,
-          'line_total': line.payable,
+        );
-        });
       }
       await batch.commit(noResult: true);
     });
   }
 
+  Future<void> _insertOrder(DatabaseExecutor txn, SaleTransaction t) async {
+    final cart = t.cart;
+
+    // A replace of the order row does not reliably cascade to its lines, so
+    // clear them first — otherwise re-saving a bill doubles its items.
+    await txn.delete(Tables.orderItems, where: 'order_id = ?', whereArgs: [t.id]);
+
+    await txn.insert(
+      Tables.orders,
+      {
+        'id': t.id,
+        'invoice_number': t.invoiceNumber,
+        'created_at': t.createdAt.millisecondsSinceEpoch,
+        'business_date': businessDateOf(t.createdAt),
+        'cashier_name': t.cashierName,
+        'terminal_id': t.terminalId,
+        'customer_id': cart.customer?.id,
+        'customer_mobile': cart.customer?.mobile,
+        'customer_name': cart.customer?.name,
+        'subtotal': cart.subtotal,
+        'line_discount': cart.lineDiscountTotal,
+        'bill_discount': cart.billDiscountTotal,
+        'loyalty_value': cart.loyaltyRedemptionValue,
+        'taxable_amount': cart.taxableAmount,
+        'tax_amount': cart.taxAmount,
+        'round_off': cart.roundOff,
+        'total': t.total,
+        'points_earned': t.pointsEarned,
+        'points_redeemed': cart.pointsRedeemed,
+        'payments_json': jsonEncode([
+          for (final p in t.payments)
+            {
+              'method': p.method.name,
+              'amount': p.amount,
+              'tendered': p.tendered,
+              'reference': p.reference,
+            },
+        ]),
+        'status': t.status.name,
+        'sync_status': pending,
+        'sync_attempts': 0,
+      },
+      conflictAlgorithm: ConflictAlgorithm.replace,
+    );
+
+    final batch = txn.batch();
+    for (final line in cart.lines) {
+      batch.insert(Tables.orderItems, {
+        'order_id': t.id,
+        'product_id': line.product.id,
+        'name': line.product.name,
+        'barcode': line.product.barcode,
+        'sku': line.product.sku,
+        'unit': line.product.unit.name,
+        'unit_price': line.product.price,
+        'quantity': line.quantity,
+        'discount': line.discountAmount,
+        'gst_rate': line.product.gstRate,
+        'tax_amount': line.taxAmount,
+        'line_total': line.payable,
+      });
+    }
+    await batch.commit(noResult: true);
+  }
+
   // ------------------------------------------------------------------ Read
   Future<List<SaleTransaction>> recent({int limit = 100}) =>
       _query(orderBy: 'created_at DESC', limit: limit);
 
-  Future<List<SaleTransaction>> forBusinessDate(DateTime day) =>
+  /// Bills for a day, optionally narrowed to one operator.
-      _query(where: 'business_date = ?', whereArgs: [businessDateOf(day)]);
+  ///
+  /// A shift report that is settled against a till has to cover exactly the
+  /// bills that cashier rang, not everything the terminal did that day.
+  Future<List<SaleTransaction>> forBusinessDate(
+    DateTime day, {
+    String? cashierName,
+  }) =>
+      _query(
+        where: cashierName == null
+            ? 'business_date = ?'
+            : 'business_date = ? AND cashier_name = ?',
+        whereArgs: [
+          businessDateOf(day),
+          if (cashierName != null) cashierName,
+        ],
+      );
 
   /// The end-of-day upload set.
   Future<List<SaleTransaction>> unsynced({int limit = 500}) => _query(
@@ -124,6 +175,25 @@ class OrderDao {
     return r.first['c']! as int;
   }
 
+  /// Stock already consumed by bills that have not yet reached the server.
+  ///
+  /// A re-import overwrites stock with the server's figure, which does not know
+  /// about these sales. Replaying them keeps the shelf count honest when the
+  /// catalogue is pulled again mid-shift.
+  Future<Map<String, double>> unsyncedStockCommitments() async {
+    final rows = await _db.rawQuery(
+      'SELECT i.product_id AS pid, SUM(i.quantity) AS q '
+      'FROM ${Tables.orderItems} i '
+      'JOIN ${Tables.orders} o ON o.id = i.order_id '
+      'WHERE o.sync_status = ? GROUP BY i.product_id',
+      [pending],
+    );
+    return {
+      for (final r in rows)
+        r['pid']! as String: (r['q']! as num).toDouble(),
+    };
+  }
+
   Future<double> salesTotalForDay(DateTime day) async {
     final r = await _db.rawQuery(
       'SELECT COALESCE(SUM(total), 0) AS t FROM ${Tables.orders} '
@@ -182,19 +252,23 @@ class OrderDao {
     if (orders.isEmpty) return;
 
     await _db.transaction((txn) async {
-      final byDate = <String, List<SaleTransaction>>{};
+      // Grouped by cashier as well as day: the archive is what a till is
+      // settled against once the bills themselves are gone.
+      final byDate = <({String date, String cashier}), List<SaleTransaction>>{};
       for (final o in orders) {
-        byDate.putIfAbsent(businessDateOf(o.createdAt), () => []).add(o);
+        final key = (date: businessDateOf(o.createdAt), cashier: o.cashierName);
+        byDate.putIfAbsent(key, () => []).add(o);
       }
 
       for (final entry in byDate.entries) {
-        final date = entry.key;
+        final date = entry.key.date;
+        final cashier = entry.key.cashier;
         final batchOrders = entry.value;
 
         final prior = await txn.query(
           Tables.dayArchive,
-          where: 'business_date = ?',
+          where: 'business_date = ? AND cashier_name = ?',
-          whereArgs: [date],
+          whereArgs: [date, cashier],
           limit: 1,
         );
         final existing = prior.isEmpty ? null : prior.first;
@@ -221,6 +295,7 @@ class OrderDao {
           Tables.dayArchive,
           {
             'business_date': date,
+            'cashier_name': cashier,
             'bill_count':
                 ((existing?['bill_count'] as int?) ?? 0) + batchOrders.length,
             'item_count': ((existing?['item_count'] as num?)?.toDouble() ?? 0) +
@@ -267,16 +342,24 @@ class OrderDao {
     });
   }
 
-  /// Archived figures for a business day, or null if nothing has synced yet.
+  /// Archived figures for a business day, one row per cashier.
-  Future<Map<String, Object?>?> dayArchive(DateTime day) async {
+  ///
-    final rows = await _db.query(
+  /// Empty when nothing has synced yet. Pass [cashierName] to scope it to a
-      Tables.dayArchive,
+  /// single operator; omit it for the whole terminal.
-      where: 'business_date = ?',
+  Future<List<Map<String, Object?>>> dayArchive(
-      whereArgs: [businessDateOf(day)],
+    DateTime day, {
-      limit: 1,
+    String? cashierName,
-    );
+  }) =>
-    return rows.isEmpty ? null : rows.first;
+      _db.query(
-  }
+        Tables.dayArchive,
+        where: cashierName == null
+            ? 'business_date = ?'
+            : 'business_date = ? AND cashier_name = ?',
+        whereArgs: [
+          businessDateOf(day),
+          if (cashierName != null) cashierName,
+        ],
+      );
 
   /// Records a failed attempt. The rows stay at `sync_status = 0`.
   Future<void> markFailed(List<String> orderIds, String error) async {
@@ -316,7 +399,7 @@ class OrderDao {
               cart: _cartFromJson(
                 jsonDecode(r['cart_json']! as String) as Map<String, Object?>,
               ),
-            ))
+            ),)
         .toList();
   }
 
@@ -389,6 +472,9 @@ class OrderDao {
     }).toList();
 
     final customerId = o['customer_id'] as String?;
+    // Rebuilt with no lifetime spend on purpose: the tier discount this shopper
+    // earned is already included in the recorded `bill_discount`, so giving the
+    // reconstruction a tier would apply it a second time.
     final customer = customerId == null
         ? null
         : Customer(
@@ -404,18 +490,37 @@ class OrderDao {
               amount: (p['amount']! as num).toDouble(),
               tendered: (p['tendered'] as num?)?.toDouble(),
               reference: p['reference'] as String?,
-            ))
+            ),)
         .toList();
 
+    // Bill-level reductions live on the order row, not on the lines, so they
+    // have to be put back explicitly. Without this the rebuilt cart bills at
+    // the undiscounted subtotal and every downstream figure — the upload
+    // payload, the day archive, the shift report — is overstated.
+    final billDiscount = (o['bill_discount']! as num).toDouble();
+
     return SaleTransaction(
       id: o['id']! as String,
       invoiceNumber: o['invoice_number']! as String,
-      cart: Cart(lines: lines, customer: customer),
+      cart: Cart(
+        lines: lines,
+        customer: customer,
+        billDiscount: billDiscount > 0
+            ? Discount(
+                type: DiscountType.flat,
+                value: billDiscount,
+                reason: 'Bill discount',
+              )
+            : Discount.none,
+        pointsRedeemed: (o['points_redeemed'] as int?) ?? 0,
+      ),
       payments: payments,
       createdAt: DateTime.fromMillisecondsSinceEpoch(o['created_at']! as int),
       cashierName: o['cashier_name']! as String,
       terminalId: o['terminal_id']! as String,
       status: TransactionStatus.values.byName(o['status']! as String),
+      storedTotal: (o['total']! as num).toDouble(),
+      storedPointsEarned: (o['points_earned'] as int?) ?? 0,
     );
   }
 

lib/data/local/sync_log_dao.dart

@@ -0,0 +1,75 @@
+import 'dart:convert';
+
+import 'package:sqflite/sqflite.dart';
+
+import '../../domain/entities/sync_event.dart';
+import 'app_database.dart';
+
+/// Persists the history of this terminal's conversations with the server.
+///
+/// Held on disk rather than in memory because it is the only record of a sync
+/// that survives the bills themselves: once the server accepts an order the row
+/// is deleted from the terminal, so without this the evidence that it ever went
+/// up disappears at the next restart.
+class SyncLogDao {
+  const SyncLogDao(this._db);
+
+  final Database _db;
+
+  Future<void> insert(SyncEvent e) async {
+    await _db.insert(
+      Tables.syncLog,
+      {
+        'id': e.id,
+        'type': e.type.name,
+        'status': e.status.name,
+        'created_at': e.createdAt.millisecondsSinceEpoch,
+        'synced_at': e.syncedAt?.millisecondsSinceEpoch,
+        'summary': e.summary,
+        'error': e.error,
+        'attempts': e.attempts,
+        'payload_json': e.payload.isEmpty ? null : jsonEncode(e.payload),
+      },
+      conflictAlgorithm: ConflictAlgorithm.replace,
+    );
+  }
+
+  /// Newest first, which is the order the events log renders.
+  Future<List<SyncEvent>> recent({int limit = 200}) async {
+    final rows = await _db.query(
+      Tables.syncLog,
+      orderBy: 'created_at DESC',
+      limit: limit,
+    );
+    return rows.map(_fromRow).toList();
+  }
+
+  /// Keeps the log from growing without bound on a terminal that runs for
+  /// months. Only ever trims the oldest entries.
+  Future<void> trim({int keep = 500}) async {
+    await _db.rawDelete(
+      'DELETE FROM ${Tables.syncLog} WHERE id NOT IN ('
+      'SELECT id FROM ${Tables.syncLog} ORDER BY created_at DESC LIMIT ?)',
+      [keep],
+    );
+  }
+
+  SyncEvent _fromRow(Map<String, Object?> r) {
+    final payload = r['payload_json'] as String?;
+    return SyncEvent(
+      id: r['id']! as String,
+      type: SyncEventType.values.byName(r['type']! as String),
+      status: SyncStatus.values.byName(r['status']! as String),
+      createdAt: DateTime.fromMillisecondsSinceEpoch(r['created_at']! as int),
+      summary: r['summary']! as String,
+      payload: payload == null
+          ? const {}
+          : (jsonDecode(payload) as Map).cast<String, Object?>(),
+      syncedAt: r['synced_at'] == null
+          ? null
+          : DateTime.fromMillisecondsSinceEpoch(r['synced_at']! as int),
+      error: r['error'] as String?,
+      attempts: (r['attempts'] as int?) ?? 0,
+    );
+  }
+}

lib/data/repositories/customer_repository_impl.dart

@@ -53,44 +53,26 @@ class CustomerRepositoryImpl implements CustomerRepository {
     return customer;
   }
 
-  @override
-  Future<Customer> recordSale({
-    required String customerId,
-    required double amount,
-    required int pointsEarned,
-    required int pointsRedeemed,
-  }) async {
-    final current = _store.customerById(customerId);
-    if (current == null) {
-      throw StateError('Customer $customerId not found.');
-    }
-    final updated = current.copyWith(
-      loyaltyPoints:
-          (current.loyaltyPoints - pointsRedeemed + pointsEarned)
-              .clamp(0, 1 << 31),
-      lifetimeSpend: (current.lifetimeSpend + amount).asMoney,
-      visitCount: current.visitCount + 1,
-      lastVisitAt: DateTime.now(),
-    );
-    await _store.putCustomer(updated);
-    return updated;
-  }
-
   @override
   Future<List<Customer>> search(String query) async {
     final q = query.trim().toLowerCase();
     if (q.isEmpty) return recent();
-    return _store.customers
+
-        .where((c) =>
+    // Stored numbers are digits only, so the query has to be reduced the same
-            c.name.toLowerCase().contains(q) || _digits(c.mobile).contains(q))
+    // way — otherwise a cashier typing "98765 43210" or "98-76" matches nothing.
-        .toList();
+    final digits = _digits(q);
+
+    return _store.customers.where((c) {
+      if (c.name.toLowerCase().contains(q)) return true;
+      return digits.isNotEmpty && _digits(c.mobile).contains(digits);
+    }).toList();
   }
 
   @override
   Future<List<Customer>> recent({int limit = 20}) async {
     final list = _store.customers.toList()
       ..sort((a, b) => (b.lastVisitAt ?? DateTime(2000))
-          .compareTo(a.lastVisitAt ?? DateTime(2000)));
+          .compareTo(a.lastVisitAt ?? DateTime(2000)),);
     return list.take(limit).toList();
   }
 }

lib/data/repositories/sync_repository_impl.dart

@@ -20,9 +20,8 @@ class SyncRepositoryImpl implements SyncRepository {
 
   static const _uuid = Uuid();
 
-  /// In-session event log. Order sync state itself lives on the order rows,
+  /// Human-readable history of sync attempts, backed by the `sync_log` table.
-  /// so this is only a human-readable history of attempts.
+  /// Order sync state itself lives on the order rows.
-  final List<SyncEvent> _events = [];
 
   @override
   bool get hasCatalogue => _store.hasCatalogue;
@@ -34,9 +33,9 @@ class SyncRepositoryImpl implements SyncRepository {
   String? get catalogueRevision => _store.catalogueRevision;
 
   @override
-  List<SyncEvent> get events => List.unmodifiable(_events.reversed);
+  List<SyncEvent> get events => _store.syncEvents;
 
-  void _log(SyncEvent e) => _events.add(e);
+  Future<void> _log(SyncEvent e) => _store.appendSyncEvent(e);
 
   // ------------------------------------------------------- Morning: import
   @override
@@ -71,7 +70,7 @@ class SyncRepositoryImpl implements SyncRepository {
         },
         attempts: 1,
       );
-      _log(event);
+      await _log(event);
       return event;
     } catch (e) {
       final event = SyncEvent(
@@ -83,7 +82,7 @@ class SyncRepositoryImpl implements SyncRepository {
         error: e.toString(),
         attempts: 1,
       );
-      _log(event);
+      await _log(event);
       return event;
     }
   }
@@ -99,39 +98,45 @@ class SyncRepositoryImpl implements SyncRepository {
   Future<ShiftReport> todayReport({
     required String terminalId,
     required String cashierName,
+    bool scopeToCashier = false,
   }) async {
     final today = DateTime.now();
+    final scope = scopeToCashier ? cashierName : null;
 
     // Bills still held locally.
-    final live = ShiftReport.fromTransactions(
+    var report = ShiftReport.fromTransactions(
-      transactions: await _store.orders.forBusinessDate(today),
+      transactions:
+          await _store.orders.forBusinessDate(today, cashierName: scope),
       businessDate: today,
       terminalId: terminalId,
       cashierName: cashierName,
     );
 
-    // Bills already uploaded and deleted survive only as archived totals.
+    // Bills already uploaded and deleted survive only as archived totals, one
-    final row = await _store.orders.dayArchive(today);
+    // row per cashier. Unscoped, every operator's row folds into the total.
-    if (row == null) return live;
+    final rows = await _store.orders.dayArchive(today, cashierName: scope);
 
-    final payments = (jsonDecode(row['payments_json']! as String)
+    for (final row in rows) {
-            as Map<String, Object?>)
+      final payments = (jsonDecode(row['payments_json']! as String)
-        .map(
+              as Map<String, Object?>)
-          (k, v) => MapEntry(
+          .map(
-            PaymentMethod.values.byName(k),
+            (k, v) => MapEntry(
-            (v! as num).toDouble(),
+              PaymentMethod.values.byName(k),
-          ),
+              (v! as num).toDouble(),
-        );
+            ),
+          );
 
-    final archived = ShiftReport.fromArchive(
+      report = ShiftReport.fromArchive(
-      row: row,
+            row: row,
-      payments: payments,
+            payments: payments,
-      businessDate: today,
+            businessDate: today,
-      terminalId: terminalId,
+            terminalId: terminalId,
-      cashierName: cashierName,
+            cashierName: cashierName,
-    );
+          ) +
+          report;
+    }
 
-    return archived + live;
+    return report;
   }
 
   @override
@@ -150,7 +155,7 @@ class SyncRepositoryImpl implements SyncRepository {
                   : DateTime.fromMillisecondsSinceEpoch(r['synced_at']! as int),
               attempts: (r['sync_attempts'] as int?) ?? 0,
               error: r['sync_error'] as String?,
-            ))
+            ),)
         .toList();
   }
 
@@ -161,71 +166,99 @@ class SyncRepositoryImpl implements SyncRepository {
   }) async {
     onProgress?.call(0.05, 'Collecting unsynced bills…');
 
-    final pending = await _store.orders.unsynced();
+    final started = DateTime.now();
-    if (pending.isEmpty) {
+    final total = await _store.orders.unsyncedCount();
+
+    if (total == 0) {
       onProgress?.call(1, 'Nothing to upload');
       return const SyncOutcome(attempted: 0, uploaded: 0);
     }
 
-    final started = DateTime.now();
+    var attempted = 0;
-    final ids = pending.map((o) => o.id).toList();
+    var uploaded = 0;
+    final syncedInvoices = <String>[];
 
-    onProgress?.call(0.35, 'Uploading ${pending.length} bills…');
+    // `unsynced()` returns a bounded page. Draining it in a loop means a day
+    // with more bills than one page still uploads completely, instead of
+    // reporting success with the remainder silently left behind.
+    while (true) {
+      final batch = await _store.orders.unsynced();
+      if (batch.isEmpty) break;
 
-    try {
+      final ids = batch.map((o) => o.id).toList();
-      final accepted = await _orderSink.pushOrders(
+      attempted += batch.length;
-        pending.map(_orderToPayload).toList(),
+
+      onProgress?.call(
+        (attempted / total).clamp(0.05, 0.9),
+        'Uploading $attempted of $total bills…',
       );
 
-      onProgress?.call(0.85, 'Clearing uploaded bills from this terminal…');
+      try {
+        final accepted = await _orderSink.pushOrders(
+          batch.map(_orderToPayload).toList(),
+        );
 
-      // Only what the server confirmed is archived and removed. Anything it
+        // Only what the server confirmed is archived and removed. Anything it
-      // did not acknowledge stays on disk.
+        // did not acknowledge stays on disk.
-      final acceptedOrders =
+        final acceptedOrders =
-          pending.where((o) => accepted.contains(o.id)).toList();
+            batch.where((o) => accepted.contains(o.id)).toList();
-      await _store.orders.archiveAndDelete(acceptedOrders);
+        await _store.orders.archiveAndDelete(acceptedOrders);
-      await _store.refreshUnsyncedCount();
+        await _store.refreshUnsyncedCount();
 
-      final rejected = ids.where((id) => !accepted.contains(id)).toList();
+        uploaded += acceptedOrders.length;
-      if (rejected.isNotEmpty) {
+        syncedInvoices.addAll(acceptedOrders.map((o) => o.invoiceNumber));
-        await _store.orders.markFailed(rejected, 'Rejected by server');
+
+        final rejected = ids.where((id) => !accepted.contains(id)).toList();
+        if (rejected.isNotEmpty) {
+          await _store.orders.markFailed(rejected, 'Rejected by server');
+          // Rejected rows stay pending, so the next page would return the same
+          // bills forever. Stop and let the cashier retry.
+          break;
+        }
+      } catch (e) {
+        // Transport failed: record the attempt but leave every row at 0.
+        await _store.orders.markFailed(ids, e.toString());
+        await _store.refreshUnsyncedCount();
+
+        final remaining = await _store.orders.unsyncedCount();
+        final pendingValue =
+            batch.fold<double>(0, (s, o) => s + o.total);
+
+        await _log(SyncEvent(
+          id: _uuid.v4(),
+          type: SyncEventType.shiftReport,
+          status: SyncStatus.failed,
+          createdAt: started,
+          summary: '$remaining bills still pending '
+              '(${Formatters.money(pendingValue)})',
+          error: e.toString(),
+          attempts: 1,
+        ),);
+
+        return SyncOutcome(
+          attempted: attempted,
+          uploaded: uploaded,
+          error: e.toString(),
+        );
       }
-
-      onProgress?.call(1, 'Done');
-
-      _log(SyncEvent(
-        id: _uuid.v4(),
-        type: SyncEventType.shiftReport,
-        status: SyncStatus.synced,
-        createdAt: started,
-        syncedAt: DateTime.now(),
-        summary: '${accepted.length} of ${pending.length} bills uploaded',
-        attempts: 1,
-      ));
-
-      return SyncOutcome(attempted: pending.length, uploaded: accepted.length);
-    } catch (e) {
-      // Transport failed: record the attempt but leave every row at 0.
-      await _store.orders.markFailed(ids, e.toString());
-      await _store.refreshUnsyncedCount();
-
-      _log(SyncEvent(
-        id: _uuid.v4(),
-        type: SyncEventType.shiftReport,
-        status: SyncStatus.failed,
-        createdAt: started,
-        summary: '${pending.length} bills still pending '
-            '(${Formatters.money(pending.fold<double>(0, (s, o) => s + o.total))})',
-        error: e.toString(),
-        attempts: 1,
-      ));
-
-      return SyncOutcome(
-        attempted: pending.length,
-        uploaded: 0,
-        error: e.toString(),
-      );
     }
+
+    onProgress?.call(1, 'Done');
+
+    // Synced bills are deleted from the terminal, so this log line is the only
+    // remaining record on the device that they went up.
+    await _log(SyncEvent(
+      id: _uuid.v4(),
+      type: SyncEventType.shiftReport,
+      status: SyncStatus.synced,
+      createdAt: started,
+      syncedAt: DateTime.now(),
+      summary: '$uploaded of $attempted bills uploaded',
+      payload: {'invoices': syncedInvoices},
+      attempts: 1,
+    ),);
+
+    return SyncOutcome(attempted: attempted, uploaded: uploaded);
   }
 
   /// The JSON body sent per order.

lib/data/repositories/transaction_repository_impl.dart

@@ -1,6 +1,8 @@
+import '../../domain/entities/customer.dart';
 import '../../domain/entities/transaction.dart';
 import '../../domain/repositories/transaction_repository.dart';
 import '../datasources/local_store.dart';
+import '../local/catalogue_dao.dart';
 
 /// All bill persistence goes straight to SQLite.
 class TransactionRepositoryImpl implements TransactionRepository {
@@ -9,11 +11,23 @@ class TransactionRepositoryImpl implements TransactionRepository {
   final LocalStore _store;
 
   @override
-  Future<SaleTransaction> save(SaleTransaction transaction) async {
+  Future<void> commitSale({
-    // Written with sync_status = 0; the end-of-day upload picks it up.
+    required SaleTransaction transaction,
-    await _store.orders.insertOrder(transaction);
+    required Map<String, double> stockMovements,
+    Customer? updatedCustomer,
+  }) async {
+    await _store.orders.commitSale(
+      transaction: transaction,
+      stockMovements: stockMovements,
+      customerRow: updatedCustomer == null
+          ? null
+          : CatalogueDao.customerToRow(updatedCustomer),
+    );
+
+    // Disk is committed; bring the read caches in line with it.
+    _store.cacheStockMovement(stockMovements);
+    if (updatedCustomer != null) _store.cacheCustomer(updatedCustomer);
     await _store.refreshUnsyncedCount();
-    return transaction;
   }
 
   @override

lib/domain/entities/cart.dart

@@ -174,11 +174,29 @@ class Cart extends Equatable {
   double get taxableAmount => (netAmount - taxAmount).asMoney;
 
   /// GST broken out per slab — required on a compliant tax invoice.
+  ///
+  /// The slabs are reconciled against [taxAmount] before being returned.
+  /// Rounding each slab on its own leaves the parts summing to a paisa either
+  /// side of the total printed on the same bill, which a tax invoice cannot
+  /// show; the residue is absorbed by the largest slab.
   Map<double, double> get taxBreakdown {
-    final map = <double, double>{};
+    final raw = <double, double>{};
     for (final line in lines) {
       final rate = line.product.gstRate;
-      map[rate] = ((map[rate] ?? 0) + line.taxAmount * _billFactor).asMoney;
+      raw[rate] = (raw[rate] ?? 0) + line.taxAmount * _billFactor;
+    }
+    if (raw.isEmpty) return const {};
+
+    final map = {
+      for (final e in raw.entries) e.key: e.value.asMoney,
+    };
+
+    final drift =
+        (taxAmount - map.values.fold(0.0, (a, b) => a + b)).asMoney;
+    if (drift != 0) {
+      final largest =
+          raw.entries.reduce((a, b) => a.value >= b.value ? a : b).key;
+      map[largest] = (map[largest]! + drift).asMoney;
     }
     return map;
   }

lib/domain/entities/customer.dart

@@ -1,6 +1,7 @@
 import 'package:equatable/equatable.dart';
 
 import '../../core/constants/app_constants.dart';
+import '../../core/utils/extensions.dart';
 
 enum Gender {
   male('Male'),
@@ -93,6 +94,26 @@ class Customer extends Equatable {
     return dob.month == now.month && dob.day == now.day;
   }
 
+  /// The shopper as they stand after a completed sale.
+  ///
+  /// Pure, so the caller can compute the new row and persist it in the same
+  /// transaction as the bill rather than as a separate write that might fail
+  /// on its own.
+  Customer applySale({
+    required double amount,
+    required int pointsEarned,
+    required int pointsRedeemed,
+    DateTime? at,
+  }) {
+    return copyWith(
+      loyaltyPoints:
+          (loyaltyPoints - pointsRedeemed + pointsEarned).clamp(0, 1 << 31),
+      lifetimeSpend: (lifetimeSpend + amount).asMoney,
+      visitCount: visitCount + 1,
+      lastVisitAt: at ?? DateTime.now(),
+    );
+  }
+
   Customer copyWith({
     String? name,
     String? email,

lib/domain/entities/shift_report.dart

@@ -88,7 +88,7 @@ class ShiftReport extends Equatable {
             t.status == TransactionStatus.completed &&
             t.createdAt.year == businessDate.year &&
             t.createdAt.month == businessDate.month &&
-            t.createdAt.day == businessDate.day)
+            t.createdAt.day == businessDate.day,)
         .toList()
       ..sort((a, b) => a.createdAt.compareTo(b.createdAt));
 
@@ -111,7 +111,7 @@ class ShiftReport extends Equatable {
           completed.fold(0.0, (s, t) => s + t.cart.taxAmount).asMoney,
       discountGiven: completed
           .fold(0.0,
-              (s, t) => s + t.cart.billDiscountTotal + t.cart.lineDiscountTotal)
+              (s, t) => s + t.cart.billDiscountTotal + t.cart.lineDiscountTotal,)
           .asMoney,
       roundOff: completed.fold(0.0, (s, t) => s + t.cart.roundOff).asMoney,
       paymentBreakdown: byMethod,

lib/domain/entities/transaction.dart

@@ -70,6 +70,8 @@ class SaleTransaction extends Equatable {
     required this.cashierName,
     this.status = TransactionStatus.completed,
     this.terminalId = 'TERM-01',
+    this.storedTotal,
+    this.storedPointsEarned,
   });
 
   final String id;
@@ -81,9 +83,20 @@ class SaleTransaction extends Equatable {
   final TransactionStatus status;
   final String terminalId;
 
+  /// The figure actually charged, as recorded at sale time.
+  ///
+  /// Set only when a bill is read back from storage. Deriving the total from
+  /// [cart] is correct for a live sale, but a rehydrated cart is a
+  /// reconstruction — if it ever loses a component the money must not move with
+  /// it. The recorded value wins whenever there is one.
+  final double? storedTotal;
+
+  /// Points issued by this sale, as recorded at sale time. See [storedTotal].
+  final int? storedPointsEarned;
+
   Customer? get customer => cart.customer;
 
-  double get total => cart.grandTotal;
+  double get total => storedTotal ?? cart.grandTotal;
 
   double get amountPaid =>
       payments.fold(0.0, (sum, p) => sum + p.amount).asMoney;
@@ -101,7 +114,7 @@ class SaleTransaction extends Equatable {
 
   bool get isSplit => payments.length > 1;
 
-  int get pointsEarned => cart.pointsEarned;
+  int get pointsEarned => storedPointsEarned ?? cart.pointsEarned;
   int get pointsRedeemed => cart.pointsRedeemed;
 
   String get paymentSummary =>

lib/domain/repositories/customer_repository.dart

@@ -11,12 +11,6 @@ abstract class CustomerRepository {
   Future<Customer> update(Customer customer);
 
   /// Applies loyalty and lifetime-spend changes once a sale completes.
-  Future<Customer> recordSale({
-    required String customerId,
-    required double amount,
-    required int pointsEarned,
-    required int pointsRedeemed,
-  });
 
   Future<List<Customer>> search(String query);
 

lib/domain/repositories/sync_repository.dart

@@ -62,9 +62,13 @@ abstract class SyncRepository {
   Future<List<SaleTransaction>> unsyncedOrders();
 
   /// Today's trading totals, read back from SQLite.
+  ///
+  /// Terminal-wide by default. Set [scopeToCashier] to cover only the bills
+  /// [cashierName] rang — what a till is actually settled against.
   Future<ShiftReport> todayReport({
     required String terminalId,
     required String cashierName,
+    bool scopeToCashier = false,
   });
 
   /// End-of-day step — uploads pending orders and flips the accepted ones to

lib/domain/repositories/transaction_repository.dart

@@ -1,7 +1,17 @@
+import '../entities/customer.dart';
 import '../entities/transaction.dart';
 
 abstract class TransactionRepository {
-  Future<SaleTransaction> save(SaleTransaction transaction);
+  /// Persists a completed sale as one atomic unit.
+  ///
+  /// The bill, the stock it consumed and the shopper's loyalty movement either
+  /// all land or none do, so a failure part-way through can never leave a
+  /// persisted bill that the cashier believes failed.
+  Future<void> commitSale({
+    required SaleTransaction transaction,
+    required Map<String, double> stockMovements,
+    Customer? updatedCustomer,
+  });
 
   Future<List<SaleTransaction>> history({int limit = 50});
 

lib/domain/usecases/checkout_sale.dart

@@ -51,10 +51,33 @@ class CheckoutSale {
     required Cart cart,
     required List<PaymentSplit> payments,
     required String cashierName,
+    String terminalId = 'TERM-01',
   }) async {
     _validate(cart, payments);
+    await _assertStockAvailable(cart);
 
     final now = DateTime.now();
+
+    // The shopper's new balance is computed before anything is written, so it
+    // can be persisted in the same transaction as the bill.
+    Customer? updatedCustomer;
+    final customer = cart.customer;
+    if (customer != null) {
+      final current = await _customers.findById(customer.id);
+      if (current == null) {
+        throw const CheckoutFailure(
+          'This customer is no longer on file. Remove them from the bill to '
+          'continue.',
+        );
+      }
+      updatedCustomer = current.applySale(
+        amount: cart.grandTotal,
+        pointsEarned: cart.pointsEarned,
+        pointsRedeemed: cart.pointsRedeemed,
+        at: now,
+      );
+    }
+
     final sequence = await _transactions.nextInvoiceSequence();
 
     final transaction = SaleTransaction(
@@ -64,24 +87,16 @@ class CheckoutSale {
       payments: payments,
       createdAt: now,
       cashierName: cashierName,
+      terminalId: terminalId,
     );
 
-    await _transactions.save(transaction);
+    await _transactions.commitSale(
-
+      transaction: transaction,
-    await _products.decrementStock({
+      stockMovements: {
-      for (final line in cart.lines) line.product.id: line.quantity,
+        for (final line in cart.lines) line.product.id: line.quantity,
-    });
+      },
-
+      updatedCustomer: updatedCustomer,
-    Customer? updatedCustomer;
+    );
-    final customer = cart.customer;
-    if (customer != null) {
-      updatedCustomer = await _customers.recordSale(
-        customerId: customer.id,
-        amount: cart.grandTotal,
-        pointsEarned: cart.pointsEarned,
-        pointsRedeemed: cart.pointsRedeemed,
-      );
-    }
 
     return CheckoutResult(
       transaction: transaction,
@@ -89,6 +104,29 @@ class CheckoutSale {
     );
   }
 
+  /// Re-checks every line against live stock.
+  ///
+  /// [CartLine.exceedsStock] reads the product snapshot taken when the item was
+  /// added, which goes stale the moment anything else sells the same item — a
+  /// parked bill resumed after its stock was sold would otherwise pass
+  /// validation and oversell.
+  Future<void> _assertStockAvailable(Cart cart) async {
+    for (final line in cart.lines) {
+      final live = await _products.findById(line.product.id);
+      if (live == null) {
+        throw CheckoutFailure(
+          '${line.product.name} is no longer in the catalogue.',
+        );
+      }
+      if (line.quantity > live.stock) {
+        throw CheckoutFailure(
+          'Only ${live.stock.toStringAsFixed(0)} ${live.unit.symbol} of '
+          '${live.name} in stock.',
+        );
+      }
+    }
+  }
+
   void _validate(Cart cart, List<PaymentSplit> payments) {
     if (cart.isEmpty) {
       throw const CheckoutFailure('Add at least one item before charging.');

lib/main.dart

@@ -76,12 +76,12 @@ class _StartupFailureApp extends StatelessWidget {
                   Container(
                     width: 56,
                     height: 56,
-                    decoration: BoxDecoration(
+                    decoration: const BoxDecoration(
                       color: AppColors.dangerSurface,
                       borderRadius: AppRadius.brMd,
                     ),
                     child: const Icon(Icons.error_outline_rounded,
-                        color: AppColors.danger, size: 28),
+                        color: AppColors.danger, size: 28,),
                   ),
                   const SizedBox(height: AppSpacing.xl),
                   const Text(

lib/presentation/auth/screens/login_screen.dart

@@ -1,5 +1,4 @@
 import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
 import 'package:flutter_animate/flutter_animate.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
@@ -408,14 +407,14 @@ class _FormPanel extends ConsumerWidget {
                     const SizedBox(height: AppSpacing.sm),
                     Container(
                       padding: const EdgeInsets.all(AppSpacing.md),
-                      decoration: BoxDecoration(
+                      decoration: const BoxDecoration(
                         color: AppColors.dangerSurface,
                         borderRadius: AppRadius.brSm,
                       ),
                       child: Row(
                         children: [
                           const Icon(Icons.error_outline_rounded,
-                              color: AppColors.danger, size: 18),
+                              color: AppColors.danger, size: 18,),
                           const SizedBox(width: AppSpacing.sm),
                           Expanded(
                             child: Text(
@@ -509,13 +508,13 @@ class _DemoHint extends StatelessWidget {
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
           const Icon(Icons.info_outline_rounded,
-              size: 17, color: AppColors.primary),
+              size: 17, color: AppColors.primary,),
           const SizedBox(width: AppSpacing.sm),
-          Expanded(
+          const Expanded(
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
-                const Text(
+                Text(
                   'Demo account',
                   style: TextStyle(
                     fontSize: 12.5,
@@ -523,10 +522,10 @@ class _DemoHint extends StatelessWidget {
                     color: AppColors.primary,
                   ),
                 ),
-                const SizedBox(height: 2),
+                SizedBox(height: 2),
                 SelectableText(
                   '${DemoCredentials.email} · ${DemoCredentials.password}',
-                  style: const TextStyle(
+                  style: TextStyle(
                     fontSize: 12,
                     color: AppColors.textSecondary,
                   ),

lib/presentation/customer/widgets/customer_capture_sheet.dart

@@ -174,7 +174,7 @@ class _CustomerCaptureSheetState
         width: 40,
         height: 4,
         margin: const EdgeInsets.symmetric(vertical: AppSpacing.md),
-        decoration: BoxDecoration(
+        decoration: const BoxDecoration(
           color: AppColors.border,
           borderRadius: AppRadius.brPill,
         ),
@@ -378,7 +378,7 @@ class _CustomerCaptureSheetState
         children: [
           Container(
             padding: const EdgeInsets.all(AppSpacing.lg),
-            decoration: BoxDecoration(
+            decoration: const BoxDecoration(
               color: AppColors.successSurface,
               borderRadius: AppRadius.brLg,
             ),
@@ -433,7 +433,7 @@ class _CustomerCaptureSheetState
                   children: [
                     Expanded(
                       child: _miniStat(
-                          '${c.loyaltyPoints}', 'points held'),
+                          '${c.loyaltyPoints}', 'points held',),
                     ),
                     Expanded(
                       child: _miniStat(

lib/presentation/modules/screens/customers_view.dart

@@ -195,9 +195,9 @@ class _CustomersViewState extends ConsumerState<CustomersView> {
                           StatusPill.tier(c.tier, dense: true),
                           Cell('${c.loyaltyPoints}', mono: true),
                           Cell(Formatters.moneyCompact(c.lifetimeSpend),
-                              mono: true, bold: true),
+                              mono: true, bold: true,),
                           Cell('${c.visitCount}', mono: true),
-                        ])
+                        ],)
                     .toList(),
               ),
             ],

lib/presentation/modules/screens/events_view.dart

@@ -146,7 +146,7 @@ class EventsView extends ConsumerWidget {
                 crossAxisAlignment: CrossAxisAlignment.start,
                 children: [
                   Icon(Icons.shield_outlined,
-                      size: 15, color: AppColors.textTertiary),
+                      size: 15, color: AppColors.textTertiary,),
                   SizedBox(width: AppSpacing.sm),
                   Expanded(
                     child: Text(
@@ -181,14 +181,14 @@ class EventsView extends ConsumerWidget {
                 .map((o) => [
                       Cell(o.invoiceNumber, bold: true, mono: true),
                       Cell(Formatters.time(o.createdAt),
-                          color: AppColors.textTertiary),
+                          color: AppColors.textTertiary,),
                       Cell(Formatters.money(o.total), mono: true, bold: true),
                       TagChip(
                         o.isSynced ? 'Synced' : 'Pending',
                         color:
                             o.isSynced ? AppColors.success : AppColors.warning,
                       ),
-                    ])
+                    ],)
                 .toList(),
           ),
         ),
@@ -227,8 +227,8 @@ class EventsView extends ConsumerWidget {
                               : AppColors.textSecondary,
                         ),
                         Cell(Formatters.time(e.createdAt),
-                            color: AppColors.textTertiary),
+                            color: AppColors.textTertiary,),
-                      ])
+                      ],)
                   .toList(),
             ),
           ),

lib/presentation/modules/screens/product_import_view.dart

@@ -102,14 +102,14 @@ class ProductImportView extends ConsumerWidget {
                           mainAxisSize: MainAxisSize.min,
                           children: [
                             Text(p.emoji,
-                                style: const TextStyle(fontSize: 17)),
+                                style: const TextStyle(fontSize: 17),),
                             const SizedBox(width: AppSpacing.sm),
                             Flexible(child: Cell(p.name, bold: true)),
                           ],
                         ),
                         Cell(p.sku, color: AppColors.textTertiary),
                         TagChip(p.category.label,
-                            color: AppColors.textSecondary),
+                            color: AppColors.textSecondary,),
                         Cell(Formatters.money(p.price), mono: true, bold: true),
                         TagChip(
                           p.isOutOfStock
@@ -121,7 +121,7 @@ class ProductImportView extends ConsumerWidget {
                                   ? AppColors.warning
                                   : AppColors.success),
                         ),
-                      ])
+                      ],)
                   .toList(),
             ),
           ),
@@ -146,13 +146,13 @@ class _NotImportedBanner extends StatelessWidget {
         borderRadius: AppRadius.brLg,
         border: Border.all(color: AppColors.warning.withValues(alpha: 0.35)),
       ),
-      child: Row(
+      child: const Row(
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
-          const Icon(Icons.cloud_download_outlined,
+          Icon(Icons.cloud_download_outlined,
-              color: AppColors.warning, size: 22),
+              color: AppColors.warning, size: 22,),
-          const SizedBox(width: AppSpacing.md),
+          SizedBox(width: AppSpacing.md),
-          const Expanded(
+          Expanded(
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
@@ -225,7 +225,7 @@ class _ImportPanel extends ConsumerWidget {
           Container(
             padding: const EdgeInsets.all(AppSpacing.md),
             margin: const EdgeInsets.only(bottom: AppSpacing.lg),
-            decoration: BoxDecoration(
+            decoration: const BoxDecoration(
               color: AppColors.dangerSurface,
               borderRadius: AppRadius.brSm,
             ),
@@ -233,7 +233,7 @@ class _ImportPanel extends ConsumerWidget {
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
                 const Icon(Icons.wifi_off_rounded,
-                    color: AppColors.danger, size: 18),
+                    color: AppColors.danger, size: 18,),
                 const SizedBox(width: AppSpacing.sm),
                 Expanded(
                   child: Text(
@@ -254,14 +254,14 @@ class _ImportPanel extends ConsumerWidget {
           Container(
             padding: const EdgeInsets.all(AppSpacing.md),
             margin: const EdgeInsets.only(bottom: AppSpacing.lg),
-            decoration: BoxDecoration(
+            decoration: const BoxDecoration(
               color: AppColors.successSurface,
               borderRadius: AppRadius.brSm,
             ),
             child: Row(
               children: [
                 const Icon(Icons.check_circle_outline_rounded,
-                    color: AppColors.success, size: 18),
+                    color: AppColors.success, size: 18,),
                 const SizedBox(width: AppSpacing.sm),
                 Expanded(
                   child: Text(
@@ -312,13 +312,13 @@ class _ImportPanel extends ConsumerWidget {
         ),
 
         const SizedBox(height: AppSpacing.lg),
-        Row(
+        const Row(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
-            const Icon(Icons.info_outline_rounded,
+            Icon(Icons.info_outline_rounded,
-                size: 15, color: AppColors.textTertiary),
+                size: 15, color: AppColors.textTertiary,),
-            const SizedBox(width: AppSpacing.sm),
+            SizedBox(width: AppSpacing.sm),
-            const Expanded(
+            Expanded(
               child: Text(
                 'After this import the terminal works entirely offline. '
                 'Sales, customers and parked bills are held locally and are '

lib/presentation/modules/screens/promos_view.dart

@@ -64,21 +64,21 @@ class _PromosViewState extends State<PromosView> {
               icon: Icons.campaign_rounded,
               caption: 'of ${_campaigns.length} configured',
             ),
-            StatTile(
+            const StatTile(
               label: 'Redemptions',
               value: '970',
               icon: Icons.confirmation_number_rounded,
               color: AppColors.info,
               caption: 'this month',
             ),
-            StatTile(
+            const StatTile(
               label: 'Discount Given',
               value: '₹48,240',
               icon: Icons.local_offer_rounded,
               color: AppColors.warning,
               caption: '2.6% of sales',
             ),
-            StatTile(
+            const StatTile(
               label: 'Incremental Sales',
               value: '₹2.14L',
               icon: Icons.trending_up_rounded,
@@ -133,7 +133,7 @@ class _PromosViewState extends State<PromosView> {
                                 borderRadius: AppRadius.brSm,
                               ),
                               child: Icon(Icons.sell_rounded,
-                                  size: 18, color: c.$6),
+                                  size: 18, color: c.$6,),
                             ),
                             const SizedBox(width: AppSpacing.md),
                             Expanded(

lib/presentation/modules/screens/settings_view.dart

@@ -167,7 +167,7 @@ class _SettingsViewState extends ConsumerState<SettingsView> {
               if (list.isEmpty) {
                 return Container(
                   padding: const EdgeInsets.all(AppSpacing.md),
-                  decoration: BoxDecoration(
+                  decoration: const BoxDecoration(
                     color: AppColors.warningSurface,
                     borderRadius: AppRadius.brSm,
                   ),
@@ -175,7 +175,7 @@ class _SettingsViewState extends ConsumerState<SettingsView> {
                     crossAxisAlignment: CrossAxisAlignment.start,
                     children: [
                       Icon(Icons.print_disabled_rounded,
-                          size: 18, color: AppColors.warning),
+                          size: 18, color: AppColors.warning,),
                       SizedBox(width: AppSpacing.sm),
                       Expanded(
                         child: Text(
@@ -235,7 +235,7 @@ class _SettingsViewState extends ConsumerState<SettingsView> {
                           final ok = await ref
                               .read(receiptServiceProvider)
                               .printTestPage(
-                                  printerUrl: settings.printerUrl);
+                                  printerUrl: settings.printerUrl,);
                           if (!context.mounted) return;
                           ScaffoldMessenger.of(context)
                             ..hideCurrentSnackBar()
@@ -245,8 +245,8 @@ class _SettingsViewState extends ConsumerState<SettingsView> {
                                   : AppColors.danger,
                               content: Text(ok
                                   ? 'Test slip sent to the printer.'
-                                  : 'Could not reach the printer.'),
+                                  : 'Could not reach the printer.',),
-                            ));
+                            ),);
                         },
                         icon: const Icon(Icons.receipt_long_rounded, size: 17),
                         label: const Text('Print test slip'),
@@ -307,9 +307,9 @@ class _SettingsViewState extends ConsumerState<SettingsView> {
                     Cell(s.role.label, color: AppColors.textSecondary),
                     s.id == current?.id
                         ? const TagChip('Signed in',
-                            color: AppColors.success)
+                            color: AppColors.success,)
                         : const SizedBox.shrink(),
-                  ])
+                  ],)
               .toList(),
         ),
       );

lib/presentation/modules/widgets/module_widgets.dart

@@ -407,7 +407,7 @@ class Cell extends StatelessWidget {
       overflow: TextOverflow.ellipsis,
       style: mono
           ? AppTypography.money(13.5,
-              weight: bold ? FontWeight.w700 : FontWeight.w500, color: color)
+              weight: bold ? FontWeight.w700 : FontWeight.w500, color: color,)
           : TextStyle(
               fontSize: 13.5,
               fontWeight: bold ? FontWeight.w600 : FontWeight.w400,

lib/presentation/payment/providers/payment_controller.dart

@@ -6,6 +6,7 @@ import '../../../app/providers.dart';
 import '../../../core/utils/extensions.dart';
 import '../../../domain/entities/transaction.dart';
 import '../../../domain/usecases/checkout_sale.dart';
+import '../../auth/providers/auth_controller.dart';
 import '../../pos/providers/cart_controller.dart';
 import '../../pos/providers/catalog_providers.dart';
 import '../../sync/providers/sync_controller.dart';
@@ -44,6 +45,7 @@ class PaymentState {
     String? error,
     bool clearError = false,
     CheckoutResult? result,
+    bool clearResult = false,
   }) {
     return PaymentState(
       splits: splits ?? this.splits,
@@ -52,7 +54,7 @@ class PaymentState {
       reference: reference ?? this.reference,
       isProcessing: isProcessing ?? this.isProcessing,
       error: clearError ? null : (error ?? this.error),
-      result: result ?? this.result,
+      result: clearResult ? null : (result ?? this.result),
     );
   }
 }
@@ -156,7 +158,10 @@ class PaymentController extends StateNotifier<PaymentState> {
     if (state.isProcessing) return null;
 
     // A single-tender sale needn't be staged first — fold it in automatically.
-    var splits = state.splits;
+    // Remembered so it can be rolled back if the sale is rejected, otherwise a
+    // retry starts with a phantom tender already staged.
+    final stagedSplits = state.splits;
+    var splits = stagedSplits;
     if (splits.isEmpty || balanceDue > 0.01) {
       addSplit();
       splits = state.splits;
@@ -168,10 +173,16 @@ class PaymentController extends StateNotifier<PaymentState> {
       final cart = _ref.read(cartControllerProvider);
       final session = _ref.read(cashierSessionProvider);
 
+      // The signed-in operator owns the bill. Falling back to the seed session
+      // stamped every sale with the same name, so a bill could not be traced to
+      // whoever actually rang it.
+      final user = _ref.read(currentUserProvider);
+
       final result = await _ref.read(checkoutSaleProvider)(
         cart: cart,
         payments: splits,
-        cashierName: session.name,
+        cashierName: user?.name ?? session.name,
+        terminalId: session.terminalId,
       );
 
       state = state.copyWith(isProcessing: false, result: result);
@@ -190,12 +201,17 @@ class PaymentController extends StateNotifier<PaymentState> {
 
       return result;
     } on CheckoutFailure catch (e) {
-      state = state.copyWith(isProcessing: false, error: e.message);
+      state = state.copyWith(
+        isProcessing: false,
+        error: e.message,
+        splits: stagedSplits,
+      );
       return null;
     } catch (e) {
       state = state.copyWith(
         isProcessing: false,
         error: 'Could not complete the sale. $e',
+        splits: stagedSplits,
       );
       return null;
     }

lib/presentation/payment/screens/payment_screen.dart

@@ -50,7 +50,7 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
   void _backspaceCash() {
     if (_cashBuffer.isEmpty) return;
     setState(
-        () => _cashBuffer = _cashBuffer.substring(0, _cashBuffer.length - 1));
+        () => _cashBuffer = _cashBuffer.substring(0, _cashBuffer.length - 1),);
     _syncCash();
   }
 
@@ -196,7 +196,7 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
                 : AppColors.primarySurface,
             child: customer == null
                 ? const Icon(Icons.person_add_alt_1_outlined,
-                    size: 19, color: AppColors.textSecondary)
+                    size: 19, color: AppColors.textSecondary,)
                 : Text(
                     Formatters.initials(customer.name),
                     style: const TextStyle(
@@ -316,7 +316,7 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
                 child: Row(
                   children: [
                     Text(e.value.method.emoji,
-                        style: const TextStyle(fontSize: 15)),
+                        style: const TextStyle(fontSize: 15),),
                     const SizedBox(width: AppSpacing.sm),
                     Expanded(
                       child: Text(
@@ -326,7 +326,7 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
                       ),
                     ),
                     Text(Formatters.money(e.value.amount),
-                        style: AppTypography.money(13.5)),
+                        style: AppTypography.money(13.5),),
                     IconButton(
                       onPressed: () => controller.removeSplit(e.key),
                       icon: const Icon(Icons.close_rounded, size: 16),
@@ -380,7 +380,7 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
             children: [
               const Text('₹',
                   style:
-                      TextStyle(fontSize: 22, color: AppColors.textTertiary)),
+                      TextStyle(fontSize: 22, color: AppColors.textTertiary),),
               const SizedBox(width: AppSpacing.sm),
               Expanded(
                 child: FittedBox(
@@ -481,7 +481,7 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
         Row(
           children: [
             Text(state.activeMethod.emoji,
-                style: const TextStyle(fontSize: 20)),
+                style: const TextStyle(fontSize: 20),),
             const SizedBox(width: AppSpacing.sm),
             Expanded(
               child: Text(
@@ -498,13 +498,13 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
           child: Container(
             width: 104,
             height: 104,
-            decoration: BoxDecoration(
+            decoration: const BoxDecoration(
               color: AppColors.primarySurface,
               borderRadius: AppRadius.brXl,
             ),
             alignment: Alignment.center,
             child: Text(state.activeMethod.emoji,
-                style: const TextStyle(fontSize: 46)),
+                style: const TextStyle(fontSize: 46),),
           ),
         ),
         const SizedBox(height: AppSpacing.lg),
@@ -543,9 +543,7 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
       onPressed: controller.balanceDue > 0
           ? () {
               controller.addSplit(
-                amount: amount == null
+                amount: amount?.clamp(0, controller.balanceDue).toDouble(),
-                    ? null
-                    : amount.clamp(0, controller.balanceDue).toDouble(),
               );
               setState(() => _cashBuffer = '');
             }
@@ -586,14 +584,14 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
                 width: double.infinity,
                 padding: const EdgeInsets.all(AppSpacing.md),
                 margin: const EdgeInsets.only(bottom: AppSpacing.md),
-                decoration: BoxDecoration(
+                decoration: const BoxDecoration(
                   color: AppColors.dangerSurface,
                   borderRadius: AppRadius.brSm,
                 ),
                 child: Row(
                   children: [
                     const Icon(Icons.error_outline_rounded,
-                        color: AppColors.danger, size: 18),
+                        color: AppColors.danger, size: 18,),
                     const SizedBox(width: AppSpacing.sm),
                     Expanded(
                       child: Text(
@@ -613,7 +611,7 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
                 child: Row(
                   children: [
                     const Icon(Icons.info_outline_rounded,
-                        size: 15, color: AppColors.textTertiary),
+                        size: 15, color: AppColors.textTertiary,),
                     const SizedBox(width: AppSpacing.sm),
                     Expanded(
                       child: Text(
@@ -634,7 +632,7 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
                           ),
                         ),
                         child: const Text('Exact',
-                            style: TextStyle(fontSize: 12.5)),
+                            style: TextStyle(fontSize: 12.5),),
                       ),
                   ],
                 ),

lib/presentation/pos/providers/cart_controller.dart

@@ -1,3 +1,5 @@
+import 'dart:async';
+
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:uuid/uuid.dart';
 
@@ -80,7 +82,7 @@ class CartController extends StateNotifier<Cart> {
         stamp: DateTime.now(),
         product: product,
         message: '${product.name} is out of stock',
-      ));
+      ),);
       return;
     }
 
@@ -98,7 +100,7 @@ class CartController extends StateNotifier<Cart> {
         product: product,
         message: 'Only ${product.stock.toStringAsFixed(0)} '
             '${product.unit.symbol} left',
-      ));
+      ),);
       return;
     }
 
@@ -110,7 +112,7 @@ class CartController extends StateNotifier<Cart> {
           quantity: quantity,
           addedAt: DateTime.now(),
         ),
-      ]);
+      ],);
     } else {
       state = state.copyWith(
         lines: _replace(existing.copyWith(quantity: requested)),
@@ -123,7 +125,7 @@ class CartController extends StateNotifier<Cart> {
       outcome: existing == null ? ScanOutcome.added : ScanOutcome.incremented,
       stamp: DateTime.now(),
       product: product,
-    ));
+    ),);
   }
 
   /// Scanner entry point. Resolves the barcode and adds it with no dialogs.
@@ -131,12 +133,13 @@ class CartController extends StateNotifier<Cart> {
     final product = await _products.findByBarcode(code);
 
     if (product == null) {
-      _sound.scanError();
+      // Deliberately not awaited — the beep must never delay the next scan.
+      unawaited(_sound.scanError());
       onFeedback(ScanFeedback(
         outcome: ScanOutcome.notFound,
         stamp: DateTime.now(),
         message: 'No product for barcode $code',
-      ));
+      ),);
       return;
     }
 
@@ -163,7 +166,7 @@ class CartController extends StateNotifier<Cart> {
         stamp: DateTime.now(),
         product: line.product,
         message: 'Only ${line.product.stock.toStringAsFixed(0)} in stock',
-      ));
+      ),);
       return;
     }
 
@@ -265,7 +268,7 @@ class CartController extends StateNotifier<Cart> {
       cart: state,
       parkedAt: DateTime.now(),
       label: label,
-    ));
+    ),);
     reset();
   }
 

lib/presentation/pos/providers/navigation_provider.dart

@@ -6,10 +6,10 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 enum PosModule {
   pos('Point of Sale', 'POS', Icons.point_of_sale_rounded, NavSection.billing),
   customers('Customers', 'Customers', Icons.people_alt_rounded,
-      NavSection.billing),
+      NavSection.billing,),
 
   productImport('Product Import', 'Product Import',
-      Icons.cloud_download_rounded, NavSection.catalogue),
+      Icons.cloud_download_rounded, NavSection.catalogue,),
   promos('Promotions', 'Promo', Icons.sell_rounded, NavSection.catalogue),
 
   events('Events', 'Events', Icons.sync_rounded, NavSection.session),

lib/presentation/pos/screens/pos_dashboard_screen.dart

@@ -13,6 +13,7 @@ import '../../modules/screens/promos_view.dart';
 import '../../modules/screens/settings_view.dart';
 import '../../sync/providers/sync_controller.dart';
 import '../providers/cart_controller.dart';
+import '../providers/catalog_providers.dart';
 import '../providers/navigation_provider.dart';
 import '../widgets/app_sidebar.dart';
 import '../widgets/billing_panel.dart';
@@ -56,6 +57,9 @@ class _PosDashboardScreenState extends ConsumerState<PosDashboardScreen> {
         // Without an imported catalogue there is nothing to resolve against.
         if (!ref.read(catalogueReadyProvider)) return;
         ref.read(activeModuleProvider.notifier).state = PosModule.pos;
+        // Drop any character the burst leaked into the search box before the
+        // scan was recognised, so the grid is not left filtered to nothing.
+        ref.read(searchQueryProvider.notifier).state = '';
         ref.read(cartControllerProvider.notifier).scanBarcode(code);
       },
     )..attach();
@@ -73,13 +77,13 @@ class _PosDashboardScreenState extends ConsumerState<PosDashboardScreen> {
       context: context,
       isScrollControlled: true,
       backgroundColor: Colors.transparent,
-      builder: (_) => FractionallySizedBox(
+      builder: (_) => const FractionallySizedBox(
         heightFactor: 0.92,
         child: ClipRRect(
-          borderRadius: const BorderRadius.vertical(
+          borderRadius: BorderRadius.vertical(
             top: Radius.circular(AppRadius.xxl),
           ),
-          child: const BillingPanel(inSheet: true),
+          child: BillingPanel(inSheet: true),
         ),
       ),
     );

lib/presentation/pos/screens/pos_view.dart

@@ -98,7 +98,7 @@ class _CatalogueRequired extends ConsumerWidget {
                   shape: BoxShape.circle,
                 ),
                 child: const Icon(Icons.cloud_download_outlined,
-                    size: 42, color: AppColors.primary),
+                    size: 42, color: AppColors.primary,),
               ),
               const SizedBox(height: AppSpacing.xxl),
               Text(
@@ -136,7 +136,7 @@ class _CatalogueRequired extends ConsumerWidget {
                     minHeight: 8,
                     backgroundColor: AppColors.divider,
                     valueColor: const AlwaysStoppedAnimation<Color>(
-                        AppColors.primary),
+                        AppColors.primary,),
                   ),
                 ),
                 const SizedBox(height: AppSpacing.lg),
@@ -146,7 +146,7 @@ class _CatalogueRequired extends ConsumerWidget {
                 Container(
                   padding: const EdgeInsets.all(AppSpacing.md),
                   margin: const EdgeInsets.only(bottom: AppSpacing.lg),
-                  decoration: BoxDecoration(
+                  decoration: const BoxDecoration(
                     color: AppColors.dangerSurface,
                     borderRadius: AppRadius.brSm,
                   ),
@@ -154,7 +154,7 @@ class _CatalogueRequired extends ConsumerWidget {
                     crossAxisAlignment: CrossAxisAlignment.start,
                     children: [
                       const Icon(Icons.wifi_off_rounded,
-                          color: AppColors.danger, size: 18),
+                          color: AppColors.danger, size: 18,),
                       const SizedBox(width: AppSpacing.sm),
                       Expanded(
                         child: Text(

lib/presentation/pos/widgets/app_sidebar.dart

@@ -245,7 +245,7 @@ class _Section extends ConsumerWidget {
               AppSpacing.sm,
             ),
             child: Text(section.label.toUpperCase(),
-                style: AppTypography.sectionLabel()),
+                style: AppTypography.sectionLabel(),),
           )
         else
           const Padding(
@@ -459,7 +459,7 @@ class _LogoutTile extends ConsumerWidget {
               mainAxisSize: MainAxisSize.min,
               children: [
                 const Icon(Icons.logout_rounded,
-                    size: 19, color: AppColors.danger),
+                    size: 19, color: AppColors.danger,),
                 if (expanded) ...[
                   const SizedBox(width: AppSpacing.md),
                   const Text(

lib/presentation/pos/widgets/billing_panel.dart

@@ -1,8 +1,9 @@
+import 'dart:async';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
 
-import '../../../core/constants/app_constants.dart';
 import '../../../core/router/app_router.dart';
 import '../../../core/theme/app_colors.dart';
 import '../../../core/theme/app_dimens.dart';
@@ -66,7 +67,7 @@ class BillingPanel extends ConsumerWidget {
         ),
         if (cart.isNotEmpty) _Summary(cart: cart),
         _Actions(cart: cart),
-      ]),
+      ],),
     );
   }
 }
@@ -101,7 +102,7 @@ class _Header extends ConsumerWidget {
             const SizedBox(width: AppSpacing.sm),
             Container(
               padding: const EdgeInsets.symmetric(horizontal: 7, vertical: 2),
-              decoration: BoxDecoration(
+              decoration: const BoxDecoration(
                 color: AppColors.primarySurface,
                 borderRadius: AppRadius.brPill,
               ),
@@ -213,13 +214,13 @@ class _Summary extends ConsumerWidget {
               horizontal: AppSpacing.md,
               vertical: AppSpacing.sm + 2,
             ),
-            decoration: BoxDecoration(
+            decoration: const BoxDecoration(
               color: AppColors.successSurface,
               borderRadius: AppRadius.brSm,
             ),
             child: Row(children: [
               const Icon(Icons.stars_rounded,
-                  size: 16, color: AppColors.success),
+                  size: 16, color: AppColors.success,),
               const SizedBox(width: AppSpacing.sm),
               Text(
                 'This sale earns +${cart.pointsEarned} pts',
@@ -229,7 +230,7 @@ class _Summary extends ConsumerWidget {
                   fontSize: 13,
                 ),
               ),
-            ]),
+            ],),
           ),
 
         _Row(label: 'Subtotal', value: Formatters.money(cart.subtotal)),
@@ -324,7 +325,7 @@ class _Summary extends ConsumerWidget {
               ),
             ),
           ),
-      ]),
+      ],),
     );
   }
 }
@@ -365,7 +366,7 @@ class _Row extends StatelessWidget {
               style: const TextStyle(
                 fontSize: 11.5,
                 color: AppColors.textTertiary,
-              )),
+              ),),
         ],
         const SizedBox(width: AppSpacing.sm),
         const Spacer(),
@@ -381,7 +382,7 @@ class _Row extends StatelessWidget {
           const SizedBox(width: AppSpacing.xs),
           Icon(trailingIcon, size: 14, color: AppColors.textTertiary),
         ],
-      ]),
+      ],),
     );
   }
 }
@@ -412,7 +413,8 @@ class _Actions extends ConsumerWidget {
                 if (ref.read(cartControllerProvider).customer == null) {
                   await showCustomerCaptureSheet(context);
                 }
-                if (context.mounted) context.push(AppRoutes.payment);
+                // Navigation result is not needed here.
+                if (context.mounted) unawaited(context.push(AppRoutes.payment));
               }
             : null,
         trailing: enabled

lib/presentation/pos/widgets/cart_fab.dart

@@ -36,7 +36,7 @@ class CartFab extends ConsumerWidget {
           child: Container(
             height: AppSizes.buttonHeightLarge,
             padding: const EdgeInsets.symmetric(horizontal: AppSpacing.xl),
-            decoration: BoxDecoration(
+            decoration: const BoxDecoration(
               borderRadius: AppRadius.brLg,
               boxShadow: AppColors.shadowLg,
             ),
@@ -79,7 +79,7 @@ class CartFab extends ConsumerWidget {
                 ),
                 const SizedBox(width: AppSpacing.sm),
                 const Icon(Icons.keyboard_arrow_up_rounded,
-                    color: Colors.white, size: 20),
+                    color: Colors.white, size: 20,),
               ],
             ),
           ),

lib/presentation/pos/widgets/cart_line_tile.dart

@@ -34,12 +34,12 @@ class CartLineTile extends StatelessWidget {
       background: Container(
         alignment: Alignment.centerRight,
         padding: const EdgeInsets.only(right: AppSpacing.xl),
-        decoration: BoxDecoration(
+        decoration: const BoxDecoration(
           color: AppColors.dangerSurface,
           borderRadius: AppRadius.brMd,
         ),
         child: const Icon(Icons.delete_outline_rounded,
-            color: AppColors.danger),
+            color: AppColors.danger,),
       ),
       child: Container(
         padding: const EdgeInsets.all(AppSpacing.md),
@@ -83,18 +83,18 @@ class CartLineTile extends StatelessWidget {
                       Formatters.money(p.price),
                       style: AppTypography.money(13.5,
                           weight: FontWeight.w600,
-                          color: AppColors.textSecondary),
+                          color: AppColors.textSecondary,),
                     ),
                     Text(' / ${p.unit.symbol}',
                         style: const TextStyle(
                           fontSize: 11.5,
                           color: AppColors.textTertiary,
-                        )),
+                        ),),
                     if (line.discount.isActive) ...[
                       const SizedBox(width: AppSpacing.sm),
                       Container(
                         padding: const EdgeInsets.symmetric(
-                            horizontal: 5, vertical: 1),
+                            horizontal: 5, vertical: 1,),
                         decoration: BoxDecoration(
                           color: AppColors.successSurface,
                           borderRadius: BorderRadius.circular(4),
@@ -109,7 +109,7 @@ class CartLineTile extends StatelessWidget {
                         ),
                       ),
                     ],
-                  ]),
+                  ],),
                 ],
               ),
             ),
@@ -121,7 +121,7 @@ class CartLineTile extends StatelessWidget {
               padding: EdgeInsets.zero,
               tooltip: 'Remove',
             ),
-          ]),
+          ],),
 
           const SizedBox(height: AppSpacing.sm),
 
@@ -162,14 +162,14 @@ class CartLineTile extends StatelessWidget {
                 ),
               ],
             ),
-          ]),
+          ],),
 
           if (line.exceedsStock)
             Padding(
               padding: const EdgeInsets.only(top: AppSpacing.sm),
               child: Row(children: [
                 const Icon(Icons.error_outline_rounded,
-                    size: 14, color: AppColors.danger),
+                    size: 14, color: AppColors.danger,),
                 const SizedBox(width: AppSpacing.xs),
                 Text(
                   'Only ${p.stock.toStringAsFixed(0)} ${p.unit.symbol} '
@@ -180,9 +180,9 @@ class CartLineTile extends StatelessWidget {
                     fontWeight: FontWeight.w600,
                   ),
                 ),
-              ]),
+              ],),
             ),
-        ]),
+        ],),
       ),
     );
   }
@@ -222,7 +222,7 @@ class _Stepper extends StatelessWidget {
           ),
         ),
         _btn(Icons.add_rounded, onIncrement),
-      ]),
+      ],),
     );
   }
 

lib/presentation/pos/widgets/category_chips.dart

@@ -108,7 +108,7 @@ class _Chip extends StatelessWidget {
                   ),
                 ),
               ],
-            ]),
+            ],),
           ),
         ),
       ),

lib/presentation/pos/widgets/customer_bar.dart

@@ -37,7 +37,7 @@ class CustomerBar extends ConsumerWidget {
               : AppColors.primarySurface,
           child: customer == null
               ? const Icon(Icons.directions_walk_rounded,
-                  size: 20, color: AppColors.textSecondary)
+                  size: 20, color: AppColors.textSecondary,)
               : Text(
                   Formatters.initials(customer.name),
                   style: const TextStyle(
@@ -65,7 +65,7 @@ class CustomerBar extends ConsumerWidget {
                   const SizedBox(width: AppSpacing.sm),
                   StatusPill.tier(customer.tier, dense: true),
                 ],
-              ]),
+              ],),
               if (customer != null)
                 Text(
                   '${Formatters.mobile(customer.mobile)}  ·  '
@@ -92,7 +92,7 @@ class CustomerBar extends ConsumerWidget {
             icon: const Icon(Icons.person_off_outlined, size: 17),
             label: const Text('Detach'),
             style: TextButton.styleFrom(
-                foregroundColor: AppColors.textSecondary),
+                foregroundColor: AppColors.textSecondary,),
           ),
         const SizedBox(width: AppSpacing.sm),
         OutlinedButton.icon(
@@ -104,7 +104,7 @@ class CustomerBar extends ConsumerWidget {
             padding: const EdgeInsets.symmetric(horizontal: AppSpacing.lg),
           ),
         ),
-      ]),
+      ],),
     );
   }
 }

lib/presentation/pos/widgets/discount_sheet.dart

@@ -116,7 +116,7 @@ class _DiscountSheetState extends State<_DiscountSheet> {
           Container(
             width: 40,
             height: 4,
-            decoration: BoxDecoration(
+            decoration: const BoxDecoration(
               color: AppColors.border,
               borderRadius: AppRadius.brPill,
             ),
@@ -124,13 +124,13 @@ class _DiscountSheetState extends State<_DiscountSheet> {
           const SizedBox(height: AppSpacing.xl),
 
           Text(widget.title,
-              style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w700)),
+              style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w700),),
           const SizedBox(height: 2),
           Text(widget.subtitle,
               style: const TextStyle(
                 fontSize: 13,
                 color: AppColors.textSecondary,
-              )),
+              ),),
           const SizedBox(height: AppSpacing.xxl),
 
           SegmentedButton<DiscountType>(
@@ -177,10 +177,10 @@ class _DiscountSheetState extends State<_DiscountSheet> {
                 .map((v) => ActionChip(
                       label: Text(_type == DiscountType.percentage
                           ? '$v%'
-                          : '₹$v'),
+                          : '₹$v',),
                       onPressed: () =>
                           setState(() => _value.text = v.toString()),
-                    ))
+                    ),)
                 .toList(),
           ),
           const SizedBox(height: AppSpacing.xxl),
@@ -205,8 +205,8 @@ class _DiscountSheetState extends State<_DiscountSheet> {
                 onPressed: _apply,
               ),
             ),
-          ]),
+          ],),
-        ]),
+        ],),
       ),
     );
   }

lib/presentation/pos/widgets/page_header.dart

@@ -133,13 +133,13 @@ class _Breadcrumb extends StatelessWidget {
         const Padding(
           padding: EdgeInsets.symmetric(horizontal: AppSpacing.xs + 2),
           child: Icon(Icons.chevron_right_rounded,
-              size: 13, color: AppColors.textTertiary),
+              size: 13, color: AppColors.textTertiary,),
         ),
         Text(module.section.label, style: style),
         const Padding(
           padding: EdgeInsets.symmetric(horizontal: AppSpacing.xs + 2),
           child: Icon(Icons.chevron_right_rounded,
-              size: 13, color: AppColors.textTertiary),
+              size: 13, color: AppColors.textTertiary,),
         ),
         Text(
           module.label,
@@ -285,7 +285,7 @@ class _ParkedBillsButton extends ConsumerWidget {
               final bill = parked[i];
               return ListTile(
                 leading: const Icon(Icons.receipt_long_rounded,
-                    color: AppColors.primary),
+                    color: AppColors.primary,),
                 title: Text(bill.displayLabel),
                 subtitle: Text(
                   '${bill.cart.lineCount} items · '

lib/presentation/pos/widgets/product_card.dart

@@ -1,6 +1,5 @@
 import 'package:flutter/material.dart';
 
-import '../../../core/constants/app_constants.dart';
 import '../../../core/theme/app_colors.dart';
 import '../../../core/theme/app_dimens.dart';
 import '../../../core/theme/app_typography.dart';
@@ -178,7 +177,7 @@ class _ProductCardState extends State<ProductCard> {
                   left: AppSpacing.sm,
                   child: Container(
                     padding: const EdgeInsets.symmetric(
-                        horizontal: 6, vertical: 2),
+                        horizontal: 6, vertical: 2,),
                     decoration: BoxDecoration(
                       color: AppColors.success,
                       borderRadius: BorderRadius.circular(5),
@@ -199,7 +198,7 @@ class _ProductCardState extends State<ProductCard> {
                   top: AppSpacing.sm,
                   right: AppSpacing.sm,
                   child: Icon(Icons.warning_amber_rounded,
-                      size: 15, color: AppColors.warning),
+                      size: 15, color: AppColors.warning,),
                 ),
 
               // Quantity badge once the item is on the bill.
@@ -243,10 +242,10 @@ class _ProductCardState extends State<ProductCard> {
                       shape: BoxShape.circle,
                     ),
                     child: const Icon(Icons.add_rounded,
-                        size: 18, color: Colors.white),
+                        size: 18, color: Colors.white,),
                   ),
                 ),
-            ]),
+            ],),
           ),
         ),
       ),

lib/presentation/pos/widgets/scan_toast.dart

@@ -67,7 +67,7 @@ class _ScanToastState extends ConsumerState<ScanToast> {
         horizontal: AppSpacing.xl,
         vertical: AppSpacing.md,
       ),
-      decoration: BoxDecoration(
+      decoration: const BoxDecoration(
         color: AppColors.textPrimary,
         borderRadius: AppRadius.brPill,
         boxShadow: AppColors.shadowLg,
@@ -110,7 +110,7 @@ class _ScanToastState extends ConsumerState<ScanToast> {
             fontSize: 13.5,
           ),
         ),
-      ]),
+      ],),
     )
         .animate(key: ValueKey(feedback.stamp))
         .fadeIn(duration: 140.ms)

lib/presentation/pos/widgets/search_field.dart

@@ -44,6 +44,13 @@ class _PosSearchFieldState extends ConsumerState<PosSearchField> {
   Widget build(BuildContext context) {
     final query = ref.watch(searchQueryProvider);
 
+    // A scan clears the query from outside this widget. Mirror that into the
+    // controller so any stray character the scanner leaked into the field goes
+    // with it.
+    ref.listen<String>(searchQueryProvider, (_, next) {
+      if (next.isEmpty && _controller.text.isNotEmpty) _controller.clear();
+    });
+
     return TextField(
       controller: _controller,
       focusNode: widget.focusNode,
@@ -80,23 +87,23 @@ class _PosSearchFieldState extends ConsumerState<PosSearchField> {
               horizontal: AppSpacing.md,
               vertical: AppSpacing.sm,
             ),
-            decoration: BoxDecoration(
+            decoration: const BoxDecoration(
               color: AppColors.primarySurface,
               borderRadius: AppRadius.brSm,
             ),
             child: const Row(mainAxisSize: MainAxisSize.min, children: [
               Icon(Icons.qr_code_scanner_rounded,
-                  size: 18, color: AppColors.primary),
+                  size: 18, color: AppColors.primary,),
               SizedBox(width: AppSpacing.xs + 2),
               Text('Scanner ready',
                   style: TextStyle(
                     color: AppColors.primary,
                     fontSize: 12,
                     fontWeight: FontWeight.w600,
-                  )),
+                  ),),
-            ]),
+            ],),
           ),
-        ]),
+        ],),
       ),
     );
   }

lib/presentation/receipt/screens/receipt_screen.dart

@@ -58,7 +58,7 @@ class _ReceiptScreenState extends ConsumerState<ReceiptScreen> {
             content: Text(
               'Printer did not respond — use Print to send it again.',
             ),
-          ));
+          ),);
       }
     });
 
@@ -112,7 +112,7 @@ class _ReceiptScreenState extends ConsumerState<ReceiptScreen> {
                         height: 480,
                         child: ReceiptPreview(transaction: txn),
                       ),
-                    ]),
+                    ],),
                   )
                 : Row(
                     crossAxisAlignment: CrossAxisAlignment.stretch,
@@ -148,7 +148,7 @@ class _ReceiptScreenState extends ConsumerState<ReceiptScreen> {
                 shape: BoxShape.circle,
               ),
               child: const Icon(Icons.check_rounded,
-                  size: 44, color: AppColors.success),
+                  size: 44, color: AppColors.success,),
             )
                 .animate()
                 .scale(
@@ -161,7 +161,7 @@ class _ReceiptScreenState extends ConsumerState<ReceiptScreen> {
           const SizedBox(height: AppSpacing.xl),
           Text('Sale complete',
               textAlign: TextAlign.center,
-              style: context.text.headlineMedium),
+              style: context.text.headlineMedium,),
           const SizedBox(height: AppSpacing.xs),
           Text(
             '${txn.invoiceNumber}  ·  ${Formatters.dateTime(txn.createdAt)}',
@@ -172,7 +172,7 @@ class _ReceiptScreenState extends ConsumerState<ReceiptScreen> {
           const SizedBox(height: AppSpacing.xxl),
           Container(
             padding: const EdgeInsets.all(AppSpacing.xl),
-            decoration: BoxDecoration(
+            decoration: const BoxDecoration(
               color: AppColors.primarySurface,
               borderRadius: AppRadius.brLg,
             ),
@@ -188,12 +188,12 @@ class _ReceiptScreenState extends ConsumerState<ReceiptScreen> {
               _row('Paid via', txn.paymentSummary),
               if (txn.changeDue > 0)
                 _row('Change returned', Formatters.money(txn.changeDue),
-                    highlight: AppColors.success),
+                    highlight: AppColors.success,),
               _row('Items', '${txn.cart.lineCount}'),
               if (txn.customer != null) ...[
                 _row('Customer', txn.customer!.name),
                 _row('Points earned', '+${txn.pointsEarned}',
-                    highlight: AppColors.success),
+                    highlight: AppColors.success,),
                 if (txn.pointsRedeemed > 0)
                   _row('Points redeemed', '-${txn.pointsRedeemed}'),
               ],
@@ -203,7 +203,7 @@ class _ReceiptScreenState extends ConsumerState<ReceiptScreen> {
                   Formatters.money(txn.cart.totalSavings),
                   highlight: AppColors.success,
                 ),
-            ]),
+            ],),
           ),
 
           const SizedBox(height: AppSpacing.xxl),
@@ -256,7 +256,7 @@ class _ReceiptScreenState extends ConsumerState<ReceiptScreen> {
                               content: Text(
                                 'Could not open WhatsApp on this device.',
                               ),
-                            ));
+                            ),);
                         },
                 ),
               ),
@@ -314,7 +314,7 @@ class _ReceiptScreenState extends ConsumerState<ReceiptScreen> {
                 style: const TextStyle(
                   fontSize: 13.5,
                   color: AppColors.textSecondary,
-                )),
+                ),),
             Text(
               value,
               style: TextStyle(

lib/presentation/receipt/widgets/receipt_preview.dart

@@ -43,7 +43,7 @@ class ReceiptPreview extends StatelessWidget {
     final discount = gross - cart.netAmount;
 
     return Container(
-      decoration: BoxDecoration(
+      decoration: const BoxDecoration(
         color: AppColors.surface,
         borderRadius: AppRadius.brLg,
         boxShadow: AppColors.shadowMd,
@@ -70,20 +70,20 @@ class ReceiptPreview extends StatelessWidget {
                             .copyWith(fontWeight: FontWeight.w700),
                       ),
                       Text(AppConstants.storeLegalName,
-                          style: AppTypography.mono(8.5)),
+                          style: AppTypography.mono(8.5),),
                       const SizedBox(height: 2),
                       Text(AppConstants.storeAddress,
                           textAlign: TextAlign.center,
-                          style: AppTypography.mono(8.5)),
+                          style: AppTypography.mono(8.5),),
                       Text('Customer care : ${AppConstants.storePhone}',
-                          style: AppTypography.mono(8.5)),
+                          style: AppTypography.mono(8.5),),
                       Text('CIN No : ${AppConstants.storeCin}',
-                          style: AppTypography.mono(8.5)),
+                          style: AppTypography.mono(8.5),),
                       Text('GSTIN : ${AppConstants.storeGstin}',
-                          style: AppTypography.mono(8.5)),
+                          style: AppTypography.mono(8.5),),
                       Text('FSSAI Lic No : ${AppConstants.storeFssai}',
-                          style: AppTypography.mono(8.5)),
+                          style: AppTypography.mono(8.5),),
-                    ]),
+                    ],),
                   ),
 
                   if (discount > 0) ...[
@@ -104,10 +104,10 @@ class ReceiptPreview extends StatelessWidget {
                     child: Column(children: [
                       Text('TAX INVOICE',
                           style: AppTypography.mono(11)
-                              .copyWith(fontWeight: FontWeight.w700)),
+                              .copyWith(fontWeight: FontWeight.w700),),
                       Text('xxxxxx Original for Recipient xxxxxx',
-                          style: AppTypography.mono(8)),
+                          style: AppTypography.mono(8),),
-                    ]),
+                    ],),
                   ),
                   const SizedBox(height: AppSpacing.sm),
 
@@ -117,7 +117,7 @@ class ReceiptPreview extends StatelessWidget {
                   _plain('Customer Type: '
                       '${txn.customer == null ? 'URD' : 'REG'}'),
                   _row('Date:${Formatters.receiptStamp(txn.createdAt)}',
-                      'Bill No:${txn.invoiceNumber.split('-').last}'),
+                      'Bill No:${txn.invoiceNumber.split('-').last}',),
                   _row(
                     'Store:${AppConstants.storeCode} '
                         'Cashier:${txn.cashierName}',
@@ -135,13 +135,13 @@ class ReceiptPreview extends StatelessWidget {
                     Expanded(flex: 34, child: _bold('Item Description')),
                     Expanded(
                         flex: 16,
-                        child: _bold('Net Price', align: TextAlign.right)),
+                        child: _bold('Net Price', align: TextAlign.right),),
                     Expanded(
-                        flex: 8, child: _bold('Qty', align: TextAlign.right)),
+                        flex: 8, child: _bold('Qty', align: TextAlign.right),),
                     Expanded(
                         flex: 18,
-                        child: _bold('Value', align: TextAlign.right)),
+                        child: _bold('Value', align: TextAlign.right),),
-                  ]),
+                  ],),
                   const SizedBox(height: 3),
 
                   for (final slab in slabs) ...[
@@ -162,28 +162,28 @@ class ReceiptPreview extends StatelessWidget {
                         child: Row(children: [
                           Expanded(
                               flex: 12,
-                              child: _cell(line.product.hsnCode ?? '-')),
+                              child: _cell(line.product.hsnCode ?? '-'),),
                           Expanded(
                               flex: 34,
                               child:
-                                  _cell(line.product.name.toUpperCase())),
+                                  _cell(line.product.name.toUpperCase()),),
                           Expanded(
                             flex: 16,
                             child: _cell(
                                 line.product.price.toStringAsFixed(2),
-                                align: TextAlign.right),
+                                align: TextAlign.right,),
                           ),
                           Expanded(
                             flex: 8,
                             child: _cell(_qty(line.quantity),
-                                align: TextAlign.right),
+                                align: TextAlign.right,),
                           ),
                           Expanded(
                             flex: 18,
                             child: _cell(line.payable.toStringAsFixed(2),
-                                align: TextAlign.right),
+                                align: TextAlign.right,),
                           ),
-                        ]),
+                        ],),
                       ),
                   ],
 
@@ -197,7 +197,7 @@ class ReceiptPreview extends StatelessWidget {
                   _amount('Gross Sales Value', gross),
                   if (discount > 0) _amount('Total Discount', discount),
                   _amount(
-                      'Net Sales Value (Inclusive of GST)', cart.netAmount),
+                      'Net Sales Value (Inclusive of GST)', cart.netAmount,),
                   if (cart.roundOff != 0)
                     _amount('Round Off', cart.roundOff),
                   _amount('Total Amount Paid', txn.total, bold: true),
@@ -206,34 +206,34 @@ class ReceiptPreview extends StatelessWidget {
                   if (txn.changeDue > 0)
                     _amount('Change Returned', txn.changeDue),
                   Text('(AMOUNT INCLUSIVE OF APPLICABLE TAXES)',
-                      style: AppTypography.mono(8)),
+                      style: AppTypography.mono(8),),
 
                   const SizedBox(height: AppSpacing.md),
 
                   // ------------------------------------------- gst breakup
                   Center(
                     child: Text('------GST Breakup Details------ Amount (INR)',
-                        style: AppTypography.mono(8.5)),
+                        style: AppTypography.mono(8.5),),
                   ),
                   const SizedBox(height: 4),
                   Row(children: [
                     Expanded(flex: 10, child: _bold('GST')),
                     Expanded(
                         flex: 20,
-                        child: _bold('Taxable', align: TextAlign.right)),
+                        child: _bold('Taxable', align: TextAlign.right),),
                     Expanded(
                         flex: 16,
-                        child: _bold('CGST', align: TextAlign.right)),
+                        child: _bold('CGST', align: TextAlign.right),),
                     Expanded(
                         flex: 16,
-                        child: _bold('SGST', align: TextAlign.right)),
+                        child: _bold('SGST', align: TextAlign.right),),
                     Expanded(
                         flex: 14,
-                        child: _bold('CESS', align: TextAlign.right)),
+                        child: _bold('CESS', align: TextAlign.right),),
                     Expanded(
                         flex: 20,
-                        child: _bold('Total', align: TextAlign.right)),
+                        child: _bold('Total', align: TextAlign.right),),
-                  ]),
+                  ],),
                   const SizedBox(height: 2),
                   for (final s in slabs)
                     Padding(
@@ -243,23 +243,23 @@ class ReceiptPreview extends StatelessWidget {
                         Expanded(
                             flex: 20,
                             child: _cell(s.taxable.toStringAsFixed(2),
-                                align: TextAlign.right)),
+                                align: TextAlign.right,),),
                         Expanded(
                             flex: 16,
                             child: _cell(s.cgst.toStringAsFixed(2),
-                                align: TextAlign.right)),
+                                align: TextAlign.right,),),
                         Expanded(
                             flex: 16,
                             child: _cell(s.sgst.toStringAsFixed(2),
-                                align: TextAlign.right)),
+                                align: TextAlign.right,),),
                         Expanded(
                             flex: 14,
-                            child: _cell('0.00', align: TextAlign.right)),
+                            child: _cell('0.00', align: TextAlign.right),),
                         Expanded(
                             flex: 20,
                             child: _cell(s.total.toStringAsFixed(2),
-                                align: TextAlign.right)),
+                                align: TextAlign.right,),),
-                      ]),
+                      ],),
                     ),
                   const _Dashes(),
                   Row(children: [
@@ -270,32 +270,32 @@ class ReceiptPreview extends StatelessWidget {
                             slabs
                                 .fold(0.0, (a, s) => a + s.taxable)
                                 .toStringAsFixed(2),
-                            align: TextAlign.right)),
+                            align: TextAlign.right,),),
                     Expanded(
                         flex: 16,
                         child: _bold(
                             slabs
                                 .fold(0.0, (a, s) => a + s.cgst)
                                 .toStringAsFixed(2),
-                            align: TextAlign.right)),
+                            align: TextAlign.right,),),
                     Expanded(
                         flex: 16,
                         child: _bold(
                             slabs
                                 .fold(0.0, (a, s) => a + s.sgst)
                                 .toStringAsFixed(2),
-                            align: TextAlign.right)),
+                            align: TextAlign.right,),),
                     Expanded(
                         flex: 14,
-                        child: _bold('0.00', align: TextAlign.right)),
+                        child: _bold('0.00', align: TextAlign.right),),
                     Expanded(
                         flex: 20,
                         child: _bold(
                             slabs
                                 .fold(0.0, (a, s) => a + s.total)
                                 .toStringAsFixed(2),
-                            align: TextAlign.right)),
+                            align: TextAlign.right,),),
-                  ]),
+                  ],),
 
                   const _Dashes(),
                   _plain('TaxInvoice# ${txn.invoiceNumber}'),
@@ -311,10 +311,10 @@ class ReceiptPreview extends StatelessWidget {
                       const SizedBox(height: AppSpacing.sm),
                       Text('* Thank You for Shopping with us *',
                           style: AppTypography.mono(10)
-                              .copyWith(fontWeight: FontWeight.w700)),
+                              .copyWith(fontWeight: FontWeight.w700),),
                       Text('Powered by Nearle POS',
-                          style: AppTypography.mono(8)),
+                          style: AppTypography.mono(8),),
-                    ]),
+                    ],),
                   ),
                 ],
               ),
@@ -322,7 +322,7 @@ class ReceiptPreview extends StatelessWidget {
           ),
         ),
         const _Perforation(top: false),
-      ]),
+      ],),
     );
   }
 
@@ -342,7 +342,7 @@ class ReceiptPreview extends StatelessWidget {
             Flexible(
               child: Text(left,
                   overflow: TextOverflow.ellipsis,
-                  style: AppTypography.mono(9)),
+                  style: AppTypography.mono(9),),
             ),
             const SizedBox(width: AppSpacing.sm),
             Text(right, style: AppTypography.mono(9)),
@@ -518,6 +518,6 @@ class _FakeBarcode extends StatelessWidget {
       ),
       const SizedBox(height: 3),
       Text(value, style: AppTypography.mono(9)),
-    ]);
+    ],);
   }
 }

lib/presentation/sync/providers/sync_controller.dart

@@ -97,7 +97,7 @@ final unsyncedCountProvider = FutureProvider<int>((ref) {
   return ref.watch(syncRepositoryProvider).unsyncedCount();
 });
 
-/// Today's totals, read back from SQLite.
+/// Everything this terminal traded today, across every operator.
 final todayReportProvider = FutureProvider<ShiftReport>((ref) {
   ref.watch(orderVersionProvider);
   final session = ref.watch(cashierSessionProvider);
@@ -109,6 +109,22 @@ final todayReportProvider = FutureProvider<ShiftReport>((ref) {
       );
 });
 
+/// Only the bills the signed-in operator rang.
+///
+/// This is the figure a cashier counts their drawer against at the end of a
+/// shift, so it must not include anyone else's sales.
+final myShiftReportProvider = FutureProvider<ShiftReport>((ref) {
+  ref.watch(orderVersionProvider);
+  final session = ref.watch(cashierSessionProvider);
+  final user = ref.watch(currentUserProvider);
+
+  return ref.watch(syncRepositoryProvider).todayReport(
+        terminalId: session.terminalId,
+        cashierName: user?.name ?? session.name,
+        scopeToCashier: true,
+      );
+});
+
 /// Per-order sync state for the events log.
 final orderSyncRowsProvider = FutureProvider<List<OrderSyncRow>>((ref) {
   ref.watch(orderVersionProvider);

lib/presentation/sync/widgets/sign_out_dialog.dart

@@ -56,7 +56,8 @@ class _SignOutDialogState extends ConsumerState<_SignOutDialog> {
 
   @override
   Widget build(BuildContext context) {
-    final report = ref.watch(todayReportProvider).value;
+    // The operator is settling their own till, so this covers only their bills.
+    final report = ref.watch(myShiftReportProvider).value;
     final pending = ref.watch(unsyncedCountProvider).value ?? 0;
     final cart = ref.watch(cartControllerProvider);
     final pushing = ref.watch(orderSyncProvider) is SyncRunning;
@@ -111,7 +112,7 @@ class _SignOutDialogState extends ConsumerState<_SignOutDialog> {
                   _row('Items sold', report.itemCount.toStringAsFixed(0)),
                   _row('Gross sales', Formatters.money(report.grossSales)),
                   _row('GST collected',
-                      Formatters.money(report.taxCollected)),
+                      Formatters.money(report.taxCollected),),
                 ],
               ],
 

test/unit/barcode_service_test.dart

@@ -0,0 +1,169 @@
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:nearle_pos/core/services/barcode_service.dart';
+
+/// The scanner is a keyboard, so the only thing separating a scan from the
+/// cashier typing is timing. These drive the handler with a controlled clock
+/// rather than real delays, so the boundary is exact.
+void main() {
+  late List<String> scans;
+  late int manualKeys;
+  late DateTime now;
+  late bool editingText;
+
+  setUp(() {
+    scans = [];
+    manualKeys = 0;
+    now = DateTime(2026, 7, 31, 10);
+    editingText = false;
+  });
+
+  BarcodeService build() => BarcodeService(
+        onScan: scans.add,
+        onManualKey: () => manualKeys++,
+        clock: () => now,
+        isEditingText: () => editingText,
+      );
+
+  KeyEvent char(String c) => KeyDownEvent(
+        physicalKey: PhysicalKeyboardKey.keyA,
+        logicalKey: LogicalKeyboardKey.keyA,
+        character: c,
+        timeStamp: Duration.zero,
+      );
+
+  KeyEvent enterKey() => const KeyDownEvent(
+        physicalKey: PhysicalKeyboardKey.enter,
+        logicalKey: LogicalKeyboardKey.enter,
+        timeStamp: Duration.zero,
+      );
+
+  /// Feeds [text] with a fixed gap between keystrokes, returning which
+  /// keystrokes the service swallowed.
+  List<bool> type(
+    BarcodeService service,
+    String text, {
+    required int gapMs,
+  }) {
+    return [
+      for (final c in text.split('')) ...[
+        () {
+          now = now.add(Duration(milliseconds: gapMs));
+          return service.handleKey(char(c));
+        }(),
+      ],
+    ];
+  }
+
+  group('scanner input', () {
+    test('a fast burst terminated by Enter is billed as a scan', () {
+      final service = build();
+
+      type(service, '8901234500011', gapMs: 5);
+      now = now.add(const Duration(milliseconds: 5));
+      final enterConsumed = service.handleKey(enterKey());
+
+      expect(scans, ['8901234500011']);
+      expect(enterConsumed, isTrue,
+          reason: 'the scanner terminator must not reach the focused field',);
+      expect(manualKeys, 0);
+    });
+
+    test('the burst is swallowed so it cannot also land in a text field', () {
+      final service = build();
+
+      final consumed = type(service, '8901234500011', gapMs: 5);
+
+      // The first keystroke cannot be judged yet — nothing has arrived to
+      // measure a gap against — so exactly one character escapes. Everything
+      // after it is recognised as machine-paced and consumed.
+      expect(consumed.first, isFalse);
+      expect(consumed.skip(1), everyElement(isTrue));
+    });
+
+    test('a scanner that sends no Enter still flushes on idle', () async {
+      final service = build();
+      type(service, '8901234500011', gapMs: 5);
+
+      expect(scans, isEmpty, reason: 'nothing has flushed yet');
+      await Future<void>.delayed(const Duration(milliseconds: 300));
+      expect(scans, ['8901234500011']);
+    });
+  });
+
+  group('human input', () {
+    test('typing at human speed is never treated as a scan', () {
+      final service = build();
+
+      final consumed = type(service, '9876543210', gapMs: 200);
+      now = now.add(const Duration(milliseconds: 200));
+      final enterConsumed = service.handleKey(enterKey());
+
+      expect(scans, isEmpty);
+      expect(consumed, everyElement(isFalse),
+          reason: 'hand-typed characters must reach the field',);
+      expect(enterConsumed, isFalse,
+          reason: 'swallowing Enter would break form submission',);
+    });
+
+    test('a fast typist in a text field does not trigger a phantom scan', () {
+      editingText = true;
+      final service = build();
+
+      // ~100ms per character is a quick typist and used to clear the bar.
+      type(service, '9876543210', gapMs: 100);
+      now = now.add(const Duration(milliseconds: 100));
+      final enterConsumed = service.handleKey(enterKey());
+
+      expect(scans, isEmpty,
+          reason: 'entering a mobile number must not jump to billing',);
+      expect(enterConsumed, isFalse);
+    });
+
+    test('the same speed does count as a scan when no field has focus', () {
+      editingText = false;
+      final service = build();
+
+      type(service, '9876543210', gapMs: 100);
+      now = now.add(const Duration(milliseconds: 100));
+      service.handleKey(enterKey());
+
+      expect(scans, ['9876543210']);
+    });
+
+    test('a pause mid-burst starts a new entry', () {
+      final service = build();
+
+      type(service, '890123', gapMs: 5);
+      now = now.add(const Duration(milliseconds: 500)); // cashier hesitates
+      type(service, '4500011', gapMs: 5);
+      now = now.add(const Duration(milliseconds: 5));
+      service.handleKey(enterKey());
+
+      expect(scans, ['4500011'],
+          reason: 'only the characters after the pause form the code',);
+    });
+  });
+
+  group('rejected input', () {
+    test('a buffer shorter than a barcode is reported as manual input', () {
+      final service = build();
+
+      type(service, 'abc', gapMs: 5);
+      now = now.add(const Duration(milliseconds: 5));
+      final enterConsumed = service.handleKey(enterKey());
+
+      expect(scans, isEmpty);
+      expect(manualKeys, 1);
+      expect(enterConsumed, isFalse);
+    });
+
+    test('non-alphanumeric characters are ignored entirely', () {
+      final service = build();
+
+      now = now.add(const Duration(milliseconds: 5));
+      expect(service.handleKey(char(r'$')), isFalse);
+      expect(scans, isEmpty);
+    });
+  });
+}

test/unit/cart_test.dart

@@ -15,7 +15,7 @@ const _item = Product(
   gstRate: 0.18,
 );
 
-Customer _silver() => Customer(
+Customer _silver() => const Customer(
       id: 'cust-1',
       name: 'Silver Shopper',
       mobile: '9876543210',
@@ -169,10 +169,10 @@ void main() {
       const cart = Cart(lines: [
         CartLine(product: _item, quantity: 1),
         CartLine(product: zeroRated, quantity: 1),
-      ]);
+      ],);
 
       final breakdown = cart.taxBreakdown;
-      expect(breakdown.keys, containsAll<double>([0.18, 0.0]));
+      expect(breakdown.keys, containsAll([0.18, 0.0]));
       expect(breakdown[0.0], 0);
       expect(breakdown[0.18]!, greaterThan(0));
     });

test/unit/checkout_test.dart

@@ -1,5 +1,6 @@
 import 'package:flutter_test/flutter_test.dart';
 import 'package:nearle_pos/data/datasources/local_store.dart';
+import 'package:nearle_pos/data/datasources/seed_data.dart';
 import 'package:nearle_pos/data/repositories/customer_repository_impl.dart';
 import 'package:nearle_pos/data/repositories/product_repository_impl.dart';
 import 'package:nearle_pos/data/repositories/transaction_repository_impl.dart';
@@ -15,10 +16,19 @@ void main() {
   late TransactionRepositoryImpl transactions;
   late CheckoutSale checkout;
 
+  setUpAll(() {
+    // The store only reaches for demo rows through these hooks, so the seed has
+    // to be registered before any test asks for a catalogue.
+    LocalStore.registerSeed(
+      products: SeedData.products,
+      customers: SeedData.customers,
+    );
+  });
+
   setUp(() async {
     store = LocalStore.instance;
     // Fresh seed for every test so stock and invoice sequence never leak.
-    await store.reset();
+    await store.reset(withCatalogue: true);
 
     products = ProductRepositoryImpl(store);
     customers = CustomerRepositoryImpl(store);

test/unit/migration_test.dart

@@ -0,0 +1,204 @@
+import 'dart:io';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:nearle_pos/data/local/app_database.dart';
+import 'package:sqflite_common_ffi/sqflite_ffi.dart';
+
+/// A terminal already in the field is running the v3 schema. Upgrading it must
+/// carry the day's archived takings across rather than dropping them, so this
+/// builds a genuine v3 database and opens it with the current code.
+void main() {
+  late Directory dir;
+  late String dbPath;
+
+  setUpAll(sqfliteFfiInit);
+
+  setUp(() async {
+    dir = await Directory.systemTemp.createTemp('nearle_migration');
+    dbPath = '${dir.path}/nearle_pos.db';
+    databaseFactory = databaseFactoryFfi;
+  });
+
+  tearDown(() async {
+    await AppDatabase.instance.close();
+    if (dir.existsSync()) dir.deleteSync(recursive: true);
+  });
+
+  /// The schema exactly as v3 shipped it.
+  Future<void> createV3Database() async {
+    final db = await databaseFactory.openDatabase(
+      dbPath,
+      options: OpenDatabaseOptions(
+        version: 3,
+        onCreate: (db, _) async {
+          await db.execute('''
+            CREATE TABLE products (
+              id TEXT PRIMARY KEY, name TEXT NOT NULL, barcode TEXT NOT NULL,
+              sku TEXT NOT NULL, category TEXT NOT NULL, price REAL NOT NULL,
+              mrp REAL, stock REAL NOT NULL DEFAULT 0, emoji TEXT,
+              image_url TEXT, unit TEXT NOT NULL DEFAULT 'piece',
+              gst_rate REAL NOT NULL DEFAULT 0.18, hsn_code TEXT, brand TEXT,
+              is_active INTEGER NOT NULL DEFAULT 1, updated_at INTEGER NOT NULL)
+          ''');
+          await db.execute('''
+            CREATE TABLE customers (
+              id TEXT PRIMARY KEY, name TEXT NOT NULL, mobile TEXT NOT NULL,
+              email TEXT, gender TEXT NOT NULL DEFAULT 'unspecified',
+              date_of_birth INTEGER, loyalty_points INTEGER NOT NULL DEFAULT 0,
+              lifetime_spend REAL NOT NULL DEFAULT 0,
+              visit_count INTEGER NOT NULL DEFAULT 0, created_at INTEGER,
+              last_visit_at INTEGER)
+          ''');
+          await db.execute('''
+            CREATE TABLE orders (
+              id TEXT PRIMARY KEY, invoice_number TEXT NOT NULL UNIQUE,
+              created_at INTEGER NOT NULL, business_date TEXT NOT NULL,
+              cashier_name TEXT NOT NULL, terminal_id TEXT NOT NULL,
+              customer_id TEXT, customer_mobile TEXT, customer_name TEXT,
+              subtotal REAL NOT NULL, line_discount REAL NOT NULL DEFAULT 0,
+              bill_discount REAL NOT NULL DEFAULT 0,
+              loyalty_value REAL NOT NULL DEFAULT 0,
+              taxable_amount REAL NOT NULL DEFAULT 0,
+              tax_amount REAL NOT NULL DEFAULT 0,
+              round_off REAL NOT NULL DEFAULT 0, total REAL NOT NULL,
+              points_earned INTEGER NOT NULL DEFAULT 0,
+              points_redeemed INTEGER NOT NULL DEFAULT 0,
+              payments_json TEXT NOT NULL,
+              status TEXT NOT NULL DEFAULT 'completed',
+              sync_status INTEGER NOT NULL DEFAULT 0, synced_at INTEGER,
+              sync_attempts INTEGER NOT NULL DEFAULT 0, sync_error TEXT)
+          ''');
+          await db.execute('''
+            CREATE TABLE order_items (
+              id INTEGER PRIMARY KEY AUTOINCREMENT, order_id TEXT NOT NULL,
+              product_id TEXT NOT NULL, name TEXT NOT NULL,
+              barcode TEXT NOT NULL, sku TEXT NOT NULL, unit TEXT NOT NULL,
+              unit_price REAL NOT NULL, quantity REAL NOT NULL,
+              discount REAL NOT NULL DEFAULT 0, gst_rate REAL NOT NULL DEFAULT 0,
+              tax_amount REAL NOT NULL DEFAULT 0, line_total REAL NOT NULL,
+              FOREIGN KEY (order_id) REFERENCES orders(id) ON DELETE CASCADE)
+          ''');
+          await db.execute('''
+            CREATE TABLE parked_bills (
+              id TEXT PRIMARY KEY, label TEXT, parked_at INTEGER NOT NULL,
+              cart_json TEXT NOT NULL)
+          ''');
+          // v3 sync_log: no payload column.
+          await db.execute('''
+            CREATE TABLE sync_log (
+              id TEXT PRIMARY KEY, type TEXT NOT NULL, status TEXT NOT NULL,
+              created_at INTEGER NOT NULL, synced_at INTEGER,
+              summary TEXT NOT NULL, error TEXT,
+              attempts INTEGER NOT NULL DEFAULT 0)
+          ''');
+          // v3 day_archive: keyed by date alone, no cashier.
+          await db.execute('''
+            CREATE TABLE day_archive (
+              business_date TEXT PRIMARY KEY,
+              bill_count INTEGER NOT NULL DEFAULT 0,
+              item_count REAL NOT NULL DEFAULT 0,
+              gross_sales REAL NOT NULL DEFAULT 0,
+              tax_collected REAL NOT NULL DEFAULT 0,
+              discount_given REAL NOT NULL DEFAULT 0,
+              round_off REAL NOT NULL DEFAULT 0,
+              points_issued INTEGER NOT NULL DEFAULT 0,
+              points_redeemed INTEGER NOT NULL DEFAULT 0,
+              payments_json TEXT NOT NULL DEFAULT '{}',
+              first_bill_at INTEGER, last_bill_at INTEGER,
+              synced_bills INTEGER NOT NULL DEFAULT 0)
+          ''');
+          await db.execute(
+            'CREATE TABLE app_meta (key TEXT PRIMARY KEY, value TEXT NOT NULL)',
+          );
+        },
+      ),
+    );
+
+    await db.insert('day_archive', {
+      'business_date': '2026-07-30',
+      'bill_count': 12,
+      'item_count': 40.0,
+      'gross_sales': 8450.0,
+      'tax_collected': 620.5,
+      'discount_given': 130.0,
+      'round_off': 1.5,
+      'points_issued': 84,
+      'points_redeemed': 20,
+      'payments_json': '{"cash":5000.0,"upi":3450.0}',
+      'first_bill_at': 1000,
+      'last_bill_at': 2000,
+      'synced_bills': 12,
+    });
+    await db.insert('app_meta', {'key': 'invoice_sequence', 'value': '12'});
+    await db.close();
+  }
+
+  test('a v3 terminal upgrades without losing its archived takings', () async {
+    await createV3Database();
+
+    await AppDatabase.instance.open(overridePath: dbPath);
+    final db = AppDatabase.instance.db;
+
+    expect(await db.getVersion(), 4);
+
+    final rows = await db.query('day_archive');
+    expect(rows, hasLength(1));
+
+    final row = rows.single;
+    expect(row['business_date'], '2026-07-30');
+    expect(row['cashier_name'], '',
+        reason: 'rows from before per-cashier attribution get an empty name',);
+    expect(row['bill_count'], 12);
+    expect(row['gross_sales'], 8450.0);
+    expect(row['tax_collected'], 620.5);
+    expect(row['payments_json'], '{"cash":5000.0,"upi":3450.0}');
+    expect(row['synced_bills'], 12);
+
+    // Unrelated state must be untouched by the migration.
+    final meta = await db.query('app_meta', where: "key = 'invoice_sequence'");
+    expect(meta.single['value'], '12');
+  });
+
+  test('the upgraded sync log accepts a payload', () async {
+    await createV3Database();
+    await AppDatabase.instance.open(overridePath: dbPath);
+    final db = AppDatabase.instance.db;
+
+    await db.insert('sync_log', {
+      'id': 'e1',
+      'type': 'shiftReport',
+      'status': 'synced',
+      'created_at': 1,
+      'summary': '3 bills uploaded',
+      'attempts': 1,
+      'payload_json': '{"invoices":["INV-1"]}',
+    });
+
+    final row = (await db.query('sync_log')).single;
+    expect(row['payload_json'], '{"invoices":["INV-1"]}');
+  });
+
+  test('the day archive now holds one row per cashier', () async {
+    await createV3Database();
+    await AppDatabase.instance.open(overridePath: dbPath);
+    final db = AppDatabase.instance.db;
+
+    for (final cashier in ['Divya', 'Rahul']) {
+      await db.insert('day_archive', {
+        'business_date': '2026-07-31',
+        'cashier_name': cashier,
+        'bill_count': 1,
+        'gross_sales': 100.0,
+        'payments_json': '{}',
+      });
+    }
+
+    final rows = await db.query(
+      'day_archive',
+      where: 'business_date = ?',
+      whereArgs: ['2026-07-31'],
+    );
+    expect(rows, hasLength(2),
+        reason: 'two cashiers on the same day must not collide',);
+  });
+}

test/unit/persistence_test.dart

@@ -0,0 +1,463 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:nearle_pos/data/datasources/local_store.dart';
+import 'package:nearle_pos/data/datasources/remote_catalogue_source.dart';
+import 'package:nearle_pos/data/datasources/seed_data.dart';
+import 'package:nearle_pos/data/repositories/customer_repository_impl.dart';
+import 'package:nearle_pos/data/repositories/product_repository_impl.dart';
+import 'package:nearle_pos/data/repositories/sync_repository_impl.dart';
+import 'package:nearle_pos/data/repositories/transaction_repository_impl.dart';
+import 'package:nearle_pos/domain/entities/cart.dart';
+import 'package:nearle_pos/domain/entities/customer.dart';
+import 'package:nearle_pos/domain/entities/shift_report.dart';
+import 'package:nearle_pos/domain/entities/sync_event.dart';
+import 'package:nearle_pos/domain/entities/transaction.dart';
+import 'package:nearle_pos/domain/usecases/checkout_sale.dart';
+
+/// Guards the boundary between a live bill and a stored one.
+///
+/// Every figure a shop is paid on survives a write to SQLite and a read back
+/// out of it. These are regressions: the read path used to rebuild a bill from
+/// its lines alone, silently dropping bill-level discounts and loyalty.
+void main() {
+  late LocalStore store;
+  late ProductRepositoryImpl products;
+  late CustomerRepositoryImpl customers;
+  late TransactionRepositoryImpl transactions;
+  late CheckoutSale checkout;
+
+  setUpAll(() {
+    LocalStore.registerSeed(
+      products: SeedData.products,
+      customers: SeedData.customers,
+    );
+  });
+
+  setUp(() async {
+    store = LocalStore.instance;
+    await store.reset(withCatalogue: true);
+
+    products = ProductRepositoryImpl(store);
+    customers = CustomerRepositoryImpl(store);
+    transactions = TransactionRepositoryImpl(store);
+    checkout = CheckoutSale(
+      productRepository: products,
+      customerRepository: customers,
+      transactionRepository: transactions,
+    );
+  });
+
+  /// A Gold member (5% tier discount) holding 400 points.
+  Future<Customer> goldMember() async {
+    final created = await customers.create(const Customer(
+      id: 'ignored',
+      name: 'Gold Shopper',
+      mobile: '9000000001',
+    ),);
+    return customers.update(
+      created.copyWith(loyaltyPoints: 400, lifetimeSpend: 60000),
+    );
+  }
+
+  group('order round trip', () {
+    test('bill discount, loyalty and total survive a write and read back',
+        () async {
+      final milk = (await products.findByBarcode('8901234500011'))!;
+      final member = await goldMember();
+
+      // 10 x 62.00 = 620 subtotal, less 5% tier (31) and a flat 50 = 81,
+      // less 40 points at 0.25 = 10. Payable 529.
+      final cart = Cart(
+        lines: [CartLine(product: milk, quantity: 10)],
+        customer: member,
+        billDiscount: const Discount(type: DiscountType.flat, value: 50),
+        pointsRedeemed: 40,
+      );
+      expect(cart.grandTotal, 529);
+      expect(cart.billDiscountTotal, 81);
+
+      final result = await checkout(
+        cart: cart,
+        payments: const [
+          PaymentSplit(method: PaymentMethod.cash, amount: 529, tendered: 529),
+        ],
+        cashierName: 'Divya',
+      );
+
+      final stored = (await transactions.history()).single;
+
+      expect(stored.total, result.transaction.total,
+          reason: 'the figure charged must not move in storage',);
+      expect(stored.total, 529);
+      expect(stored.cart.billDiscountTotal, 81);
+      expect(stored.cart.loyaltyRedemptionValue, 10);
+      expect(stored.cart.pointsRedeemed, 40);
+      expect(stored.cart.taxAmount, cart.taxAmount);
+      expect(stored.cart.subtotal, 620);
+    });
+
+    test('a rebuilt bill does not re-apply the tier discount', () async {
+      final milk = (await products.findByBarcode('8901234500011'))!;
+      final member = await goldMember();
+
+      final cart = Cart(
+        lines: [CartLine(product: milk, quantity: 10)],
+        customer: member,
+      );
+      // 620 less the 5% tier discount only.
+      expect(cart.grandTotal, 589);
+
+      await checkout(
+        cart: cart,
+        payments: const [
+          PaymentSplit(method: PaymentMethod.cash, amount: 589, tendered: 600),
+        ],
+        cashierName: 'Divya',
+      );
+
+      final stored = (await transactions.history()).single;
+      expect(stored.cart.billDiscountTotal, 31);
+      expect(stored.total, 589);
+    });
+
+    test('the shift report reads back the amount actually charged', () async {
+      final milk = (await products.findByBarcode('8901234500011'))!;
+      final member = await goldMember();
+
+      await checkout(
+        cart: Cart(
+          lines: [CartLine(product: milk, quantity: 10)],
+          customer: member,
+          billDiscount: const Discount(type: DiscountType.flat, value: 50),
+          pointsRedeemed: 40,
+        ),
+        payments: const [
+          PaymentSplit(method: PaymentMethod.cash, amount: 529, tendered: 529),
+        ],
+        cashierName: 'Divya',
+      );
+
+      final report = ShiftReport.fromTransactions(
+        transactions: await transactions.history(),
+        businessDate: DateTime.now(),
+        terminalId: 'TERM-01',
+        cashierName: 'Divya',
+      );
+
+      expect(report.grossSales, 529);
+      expect(report.discountGiven, 81);
+      expect(report.loyaltyPointsRedeemed, 40);
+    });
+
+    test('the bill is stamped with the operator who rang it', () async {
+      final milk = (await products.findByBarcode('8901234500011'))!;
+
+      await checkout(
+        cart: Cart(lines: [CartLine(product: milk, quantity: 1)]),
+        payments: const [
+          PaymentSplit(method: PaymentMethod.cash, amount: 62, tendered: 100),
+        ],
+        cashierName: 'Rahul',
+        terminalId: 'TERM-07',
+      );
+
+      final stored = (await transactions.history()).single;
+      expect(stored.cashierName, 'Rahul');
+      expect(stored.terminalId, 'TERM-07');
+    });
+  });
+
+  group('stock safety', () {
+    test('a resumed parked bill is re-checked against live stock', () async {
+      final milk = (await products.findByBarcode('8901234500011'))!;
+
+      await transactions.park(ParkedBill(
+        id: 'p-1',
+        cart: Cart(lines: [CartLine(product: milk, quantity: milk.stock)]),
+        parkedAt: DateTime.now(),
+      ),);
+
+      // The same stock is sold on another bill in the meantime.
+      await products.decrementStock({milk.id: milk.stock});
+
+      final resumed = (await transactions.parkedBills()).single;
+
+      await expectLater(
+        checkout(
+          cart: resumed.cart,
+          payments: [
+            PaymentSplit(
+              method: PaymentMethod.cash,
+              amount: resumed.cart.grandTotal,
+              tendered: resumed.cart.grandTotal,
+            ),
+          ],
+          cashierName: 'Divya',
+        ),
+        throwsA(isA<CheckoutFailure>()),
+      );
+
+      expect(await transactions.history(), isEmpty);
+    });
+
+    test('a re-import does not restore stock already sold', () async {
+      final milk = (await products.findByBarcode('8901234500011'))!;
+      final opening = milk.stock;
+
+      await checkout(
+        cart: Cart(lines: [CartLine(product: milk, quantity: 4)]),
+        payments: const [
+          PaymentSplit(method: PaymentMethod.cash, amount: 248, tendered: 250),
+        ],
+        cashierName: 'Divya',
+      );
+      expect((await products.findByBarcode('8901234500011'))!.stock,
+          opening - 4,);
+
+      // The morning catalogue is pulled again before the bills went up.
+      await store.importCatalogue(
+        products: SeedData.products(),
+        customers: SeedData.customers(),
+        revision: 'seed-2',
+        at: DateTime.now(),
+      );
+
+      expect(
+        (await products.findByBarcode('8901234500011'))!.stock,
+        opening - 4,
+        reason: 'units sold on unsynced bills must not reappear on the shelf',
+      );
+    });
+  });
+
+  group('atomicity', () {
+    test('nothing is persisted when the sale cannot be completed', () async {
+      final milk = (await products.findByBarcode('8901234500011'))!;
+      final opening = milk.stock;
+
+      // A customer that was never written to the database.
+      const ghost = Customer(id: 'missing', name: 'Ghost', mobile: '9999999999');
+
+      await expectLater(
+        checkout(
+          cart: Cart(
+            lines: [CartLine(product: milk, quantity: 2)],
+            customer: ghost,
+          ),
+          payments: const [
+            PaymentSplit(method: PaymentMethod.cash, amount: 124, tendered: 124),
+          ],
+          cashierName: 'Divya',
+        ),
+        throwsA(isA<CheckoutFailure>()),
+      );
+
+      expect(await transactions.history(), isEmpty,
+          reason: 'a failed sale must not leave a bill behind',);
+      expect((await products.findByBarcode('8901234500011'))!.stock, opening,
+          reason: 'a failed sale must not consume stock',);
+    });
+
+    test('concurrent checkouts never share an invoice sequence', () async {
+      final numbers = await Future.wait(
+        List.generate(25, (_) => transactions.nextInvoiceSequence()),
+      );
+      expect(numbers.toSet().length, numbers.length);
+    });
+  });
+
+  group('end of day', () {
+    test('the archived day totals match what was charged', () async {
+      final sync = SyncRepositoryImpl(
+        store,
+        RemoteCatalogueSource(isOffline: () => false),
+        RemoteOrderSink(isOffline: () => false),
+      );
+
+      final milk = (await products.findByBarcode('8901234500011'))!;
+      final member = await goldMember();
+
+      await checkout(
+        cart: Cart(
+          lines: [CartLine(product: milk, quantity: 10)],
+          customer: member,
+          billDiscount: const Discount(type: DiscountType.flat, value: 50),
+          pointsRedeemed: 40,
+        ),
+        payments: const [
+          PaymentSplit(method: PaymentMethod.cash, amount: 529, tendered: 529),
+        ],
+        cashierName: 'Divya',
+      );
+
+      final outcome = await sync.syncOrders();
+      expect(outcome.uploaded, 1);
+      expect(await sync.unsyncedCount(), 0);
+
+      // Synced bills are deleted, so today's figures now come from the archive.
+      // A wrong row here is permanent — there is nothing left to recompute from.
+      final report = await sync.todayReport(
+        terminalId: 'TERM-01',
+        cashierName: 'Divya',
+      );
+
+      expect(report.billCount, 1);
+      expect(report.grossSales, 529);
+      expect(report.discountGiven, 81);
+      expect(report.loyaltyPointsRedeemed, 40);
+      expect(report.paymentBreakdown[PaymentMethod.cash], 529);
+    });
+  });
+
+  group('sync log', () {
+    test('survives a restart, because it outlives the bills it describes',
+        () async {
+      final sync = SyncRepositoryImpl(
+        store,
+        RemoteCatalogueSource(isOffline: () => false),
+        RemoteOrderSink(isOffline: () => false),
+      );
+
+      final milk = (await products.findByBarcode('8901234500011'))!;
+      await checkout(
+        cart: Cart(lines: [CartLine(product: milk, quantity: 1)]),
+        payments: const [
+          PaymentSplit(method: PaymentMethod.cash, amount: 62, tendered: 62),
+        ],
+        cashierName: 'Divya',
+      );
+      await sync.syncOrders();
+
+      expect(sync.events, isNotEmpty);
+      final summary = sync.events.first.summary;
+
+      // The cache is dropped and rebuilt from disk, as it is on a cold start.
+      await store.hydrate();
+
+      expect(sync.events, isNotEmpty,
+          reason: 'the only record that those bills went up must persist',);
+      expect(sync.events.first.summary, summary);
+      expect(sync.events.first.payload['invoices'], isNotEmpty);
+    });
+
+    test('a failed import is recorded with its error', () async {
+      final sync = SyncRepositoryImpl(
+        store,
+        RemoteCatalogueSource(isOffline: () => true),
+        RemoteOrderSink(isOffline: () => true),
+      );
+
+      await sync.importCatalogue();
+      await store.hydrate();
+
+      expect(sync.events.first.status, SyncStatus.failed);
+      expect(sync.events.first.error, isNotNull);
+    });
+  });
+
+  group('shift report scoping', () {
+    Future<void> sell(String cashier, double qty) async {
+      final milk = (await products.findByBarcode('8901234500011'))!;
+      final due = Cart(lines: [CartLine(product: milk, quantity: qty)]).grandTotal;
+      await checkout(
+        cart: Cart(lines: [CartLine(product: milk, quantity: qty)]),
+        payments: [
+          PaymentSplit(method: PaymentMethod.cash, amount: due, tendered: due),
+        ],
+        cashierName: cashier,
+      );
+    }
+
+    test('a cashier settles their own till, not the terminal', () async {
+      final sync = SyncRepositoryImpl(
+        store,
+        RemoteCatalogueSource(isOffline: () => false),
+        RemoteOrderSink(isOffline: () => false),
+      );
+
+      await sell('Divya', 2); // 124
+      await sell('Rahul', 3); // 186
+
+      final divya = await sync.todayReport(
+        terminalId: 'TERM-01',
+        cashierName: 'Divya',
+        scopeToCashier: true,
+      );
+      final terminal = await sync.todayReport(
+        terminalId: 'TERM-01',
+        cashierName: 'Divya',
+      );
+
+      expect(divya.billCount, 1);
+      expect(divya.grossSales, 124);
+      expect(terminal.billCount, 2);
+      expect(terminal.grossSales, 310);
+    });
+
+    test('scoping holds after the bills are uploaded and deleted', () async {
+      final sync = SyncRepositoryImpl(
+        store,
+        RemoteCatalogueSource(isOffline: () => false),
+        RemoteOrderSink(isOffline: () => false),
+      );
+
+      await sell('Divya', 2);
+      await sell('Rahul', 3);
+      await sync.syncOrders();
+      expect(await sync.unsyncedCount(), 0);
+
+      final divya = await sync.todayReport(
+        terminalId: 'TERM-01',
+        cashierName: 'Divya',
+        scopeToCashier: true,
+      );
+      final terminal = await sync.todayReport(
+        terminalId: 'TERM-01',
+        cashierName: 'Divya',
+      );
+
+      expect(divya.grossSales, 124,
+          reason: 'the archive must keep each cashier separable',);
+      expect(divya.billCount, 1);
+      expect(terminal.grossSales, 310);
+      expect(terminal.billCount, 2);
+    });
+  });
+
+  group('customer lookup', () {
+    test('a mobile number matches however the cashier punctuates it', () async {
+      await customers.create(const Customer(
+        id: 'ignored',
+        name: 'Punctuation Test',
+        mobile: '9000000042',
+      ),);
+
+      for (final query in ['9000000042', '90000 00042', '90-000-00042']) {
+        expect(
+          (await customers.search(query)).map((c) => c.name),
+          contains('Punctuation Test'),
+          reason: 'searching "$query" should find the customer',
+        );
+      }
+    });
+  });
+
+  group('tax invoice', () {
+    test('the slab breakdown sums to the GST charged', () async {
+      // Two different slabs plus a bill discount, so apportioning is in play.
+      final milk = (await products.findByBarcode('8901234500011'))!; // 5%
+      final all = await products.getAll();
+      final eighteen = all.firstWhere((p) => p.gstRate == 0.18);
+
+      final cart = Cart(
+        lines: [
+          CartLine(product: milk, quantity: 3),
+          CartLine(product: eighteen, quantity: 7),
+        ],
+        billDiscount: const Discount(type: DiscountType.percentage, value: 13),
+      );
+
+      final summed = cart.taxBreakdown.values.fold(0.0, (a, b) => a + b);
+      expect(summed, closeTo(cart.taxAmount, 0.0001));
+    });
+  });
+}

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);

test/widget_test.dart

@@ -1,30 +0,0 @@
-// This is a basic Flutter widget test.
-//
-// To perform an interaction with a widget in your test, use the WidgetTester
-// utility in the flutter_test package. For example, you can send tap and scroll
-// gestures. You can also use WidgetTester to find child widgets in the widget
-// tree, read text, and verify that the values of widget properties are correct.
-
-import 'package:flutter/material.dart';
-import 'package:flutter_test/flutter_test.dart';
-
-import 'package:nearle_pos/main.dart';
-
-void main() {
-  testWidgets('Counter increments smoke test', (WidgetTester tester) async {
-    // Build our app and trigger a frame.
-    await tester.pumpWidget(const MyApp());
-
-    // Verify that our counter starts at 0.
-    expect(find.text('0'), findsOneWidget);
-    expect(find.text('1'), findsNothing);
-
-    // Tap the '+' icon and trigger a frame.
-    await tester.tap(find.byIcon(Icons.add));
-    await tester.pump();
-
-    // Verify that our counter has incremented.
-    expect(find.text('0'), findsNothing);
-    expect(find.text('1'), findsOneWidget);
-  });
-}