Fix transfer functoin, add display for numer of pending locos

lib/components/pages/traction/traction_page.dart

@@ -12,6 +12,7 @@ class TractionPage extends StatefulWidget {
     this.selectionMode = false,
     this.selectionSingle = false,
     this.replacementPendingLocoId,
+    this.transferFromLabel,
     this.transferFromLocoId,
     this.onSelect,
     this.selectedKeys = const {},
@@ -20,6 +21,7 @@ class TractionPage extends StatefulWidget {
   final bool selectionMode;
   final bool selectionSingle;
   final int? replacementPendingLocoId;
+  final String? transferFromLabel;
   final int? transferFromLocoId;
   final ValueChanged<LocoSummary>? onSelect;
   final Set<String> selectedKeys;
@@ -61,6 +63,8 @@ class _TractionPageState extends State<TractionPage> {
   static const int _pageSize = 100;
   int _lastTractionOffset = 0;
   String? _lastQuerySignature;
+  String? _transferFromLabel;
+  bool _isSearching = false;
 
   @override
   void initState() {
@@ -74,6 +78,7 @@ class _TractionPageState extends State<TractionPage> {
     if (!_initialised) {
       _initialised = true;
       _selectedKeys = {...widget.selectedKeys};
+      _transferFromLabel = widget.transferFromLabel;
       WidgetsBinding.instance.addPostFrameCallback((_) {
         _initialLoad();
       });
@@ -82,12 +87,16 @@ class _TractionPageState extends State<TractionPage> {
 
   Future<void> _initialLoad() async {
     final data = context.read<DataService>();
+    final auth = context.read<AuthService>();
     await _restoreSearchState();
     if (_lastTractionOffset == 0 && data.traction.length > _pageSize) {
       _lastTractionOffset = data.traction.length - _pageSize;
     }
     data.fetchClassList();
     data.fetchEventFields();
+    if (auth.isElevated) {
+      unawaited(data.fetchPendingLocoCount());
+    }
     await _refreshTraction();
   }
 
@@ -153,6 +162,7 @@ class _TractionPageState extends State<TractionPage> {
     bool append = false,
     bool preservePosition = true,
   }) async {
+    _setState(() => _isSearching = true);
     final data = context.read<DataService>();
     final filters = <String, dynamic>{};
     final name = _nameController.text.trim();
@@ -211,6 +221,7 @@ class _TractionPageState extends State<TractionPage> {
     }
 
     await _persistSearchState();
+    _setState(() => _isSearching = false);
   }
 
   void _clearFilters() {
@@ -309,6 +320,7 @@ class _TractionPageState extends State<TractionPage> {
     final isMobile = MediaQuery.of(context).size.width < 700;
     _syncControllersForFields(data.eventFields);
     final extraFields = _activeEventFields(data.eventFields);
+    final transferBanner = _buildTransferBanner(data);
 
     final slivers = <Widget>[
       SliverPadding(
@@ -338,6 +350,10 @@ class _TractionPageState extends State<TractionPage> {
                   _buildHeaderActions(context, isMobile),
                 ],
               ),
+              if (transferBanner != null) ...[
+                const SizedBox(height: 8),
+                transferBanner,
+              ],
               const SizedBox(height: 12),
               Card(
                 child: Padding(
@@ -487,8 +503,25 @@ class _TractionPageState extends State<TractionPage> {
                           ),
                           ElevatedButton.icon(
                             onPressed: _refreshTraction,
-                            icon: const Icon(Icons.search),
-                            label: const Text('Search'),
+                            icon: (_isSearching || data.isTractionLoading)
+                                ? SizedBox(
+                                    width: 16,
+                                    height: 16,
+                                    child: CircularProgressIndicator(
+                                      strokeWidth: 2,
+                                      valueColor: AlwaysStoppedAnimation<Color>(
+                                        Theme.of(context)
+                                            .colorScheme
+                                            .onPrimary,
+                                      ),
+                                    ),
+                                  )
+                                : const Icon(Icons.search),
+                            label: Text(
+                              (_isSearching || data.isTractionLoading)
+                                  ? 'Searching...'
+                                  : 'Search',
+                            ),
                           ),
                         ],
                       ),
@@ -613,6 +646,12 @@ class _TractionPageState extends State<TractionPage> {
 
   Widget _buildHeaderActions(BuildContext context, bool isMobile) {
     final isElevated = context.read<AuthService>().isElevated;
+    final data = context.watch<DataService>();
+    final pendingCount = data.pendingLocoCount;
+    String? pendingLabel;
+    if (pendingCount > 0) {
+      pendingLabel = pendingCount > 999 ? '999+' : pendingCount.toString();
+    }
     final refreshButton = IconButton(
       tooltip: 'Refresh',
       onPressed: _refreshTraction,
@@ -659,6 +698,7 @@ class _TractionPageState extends State<TractionPage> {
                   try {
                     await context.push('/traction/pending');
                     if (!mounted) return;
+                    await data.fetchPendingLocoCount();
                   } catch (_) {
                     if (!mounted) return;
                     messenger.showSnackBar(
@@ -693,9 +733,16 @@ class _TractionPageState extends State<TractionPage> {
               }
               if (hasAdminActions) {
                 items.add(
-                  const PopupMenuItem(
+                  PopupMenuItem(
                     value: _TractionMoreAction.adminPending,
-                    child: Text('Pending locos'),
+                    child: Row(
+                      children: [
+                        const Text('Pending locos'),
+                        const Spacer(),
+                        if (pendingLabel != null)
+                          _countChip(context, pendingLabel),
+                      ],
+                    ),
                   ),
                 );
               }
@@ -705,7 +752,16 @@ class _TractionPageState extends State<TractionPage> {
               child: FilledButton.tonalIcon(
                 onPressed: () {},
                 icon: const Icon(Icons.more_horiz),
-                label: const Text('More'),
+                label: Row(
+                  mainAxisSize: MainAxisSize.min,
+                  children: [
+                    const Text('More'),
+                    if (pendingLabel != null) ...[
+                      const SizedBox(width: 6),
+                      _countChip(context, pendingLabel),
+                    ],
+                  ],
+                ),
               ),
             ),
           );
@@ -1208,13 +1264,35 @@ class _TractionPageState extends State<TractionPage> {
     if (fromId == null) return;
     final navContext = context;
     final messenger = ScaffoldMessenger.of(navContext);
+    final data = navContext.read<DataService>();
+    final fromLoco = data.traction.firstWhere(
+      (l) => l.id == fromId,
+      orElse: () => target,
+    );
+    final fromLabel = '${fromLoco.locoClass} ${fromLoco.number}'.trim();
+    final toLabel = '${target.locoClass} ${target.number}'.trim();
     final confirmed = await showDialog<bool>(
       context: navContext,
       builder: (dialogContext) {
         return AlertDialog(
           title: const Text('Transfer allocations?'),
-          content: Text(
-            'Transfer all allocations from this loco to ${target.locoClass} ${target.number}?',
+          content: Column(
+            mainAxisSize: MainAxisSize.min,
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Text(
+                'Transfer all allocations from $fromLabel to $toLabel?',
+              ),
+              const SizedBox(height: 12),
+              Text(
+                'From: $fromLabel',
+                style: Theme.of(dialogContext)
+                    .textTheme
+                    .bodyMedium
+                    ?.copyWith(fontWeight: FontWeight.w700),
+              ),
+              Text('To: $toLabel'),
+            ],
           ),
           actions: [
             TextButton(
@@ -1273,6 +1351,69 @@ class _TractionPageState extends State<TractionPage> {
     );
   }
 
+  Widget? _buildTransferBanner(DataService data) {
+    final fromId = _transferFromLocoId;
+    if (fromId == null) return null;
+    if (_transferFromLabel == null || _transferFromLabel!.trim().isEmpty) {
+      final from = data.traction.firstWhere(
+        (loco) => loco.id == fromId,
+        orElse: () => LocoSummary(
+          locoId: fromId,
+          locoType: '',
+          locoNumber: '',
+          locoName: '',
+          locoClass: '',
+          locoOperator: '',
+        ),
+      );
+      final fallbackLabel = '${from.locoClass} ${from.number}'.trim().isEmpty
+          ? 'Loco $fromId'
+          : '${from.locoClass} ${from.number}'.trim();
+      _transferFromLabel = fallbackLabel;
+    }
+    final label = _transferFromLabel ?? 'Loco $fromId';
+    return Container(
+      width: double.infinity,
+      padding: const EdgeInsets.all(12),
+      decoration: BoxDecoration(
+        color: Colors.orange.withValues(alpha: 0.1),
+        borderRadius: BorderRadius.circular(8),
+        border: Border.all(color: Colors.orange.withValues(alpha: 0.4)),
+      ),
+      child: Row(
+        children: [
+          const Icon(Icons.swap_horiz, color: Colors.orange),
+          const SizedBox(width: 8),
+          Expanded(
+            child: Text(
+              'Transferring allocations from $label. Select a loco to transfer to.',
+              style: const TextStyle(fontWeight: FontWeight.w600),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _countChip(BuildContext context, String label) {
+    final scheme = Theme.of(context).colorScheme;
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
+      decoration: BoxDecoration(
+        color: scheme.primary,
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Text(
+        label,
+        style: TextStyle(
+          color: scheme.onPrimary,
+          fontWeight: FontWeight.w700,
+          fontSize: 12,
+        ),
+      ),
+    );
+  }
+
   Widget _buildFilterInput(
     BuildContext context,
     EventField field,
@@ -1395,12 +1536,16 @@ class _TractionPageState extends State<TractionPage> {
                 onOpenLegs: () => _openLegs(loco),
                 onActionComplete: _refreshTraction,
                 onToggleSelect: widget.selectionMode &&
-                        widget.replacementPendingLocoId == null
+                        widget.replacementPendingLocoId == null &&
+                        (widget.transferFromLocoId == null ||
+                            widget.transferFromLocoId != loco.id)
                     ? () => _toggleSelection(loco)
                     : null,
                 onReplacePending: widget.selectionMode &&
                         widget.selectionSingle &&
-                        widget.replacementPendingLocoId != null
+                        widget.replacementPendingLocoId != null &&
+                        (widget.transferFromLocoId == null ||
+                            widget.transferFromLocoId != loco.id)
                     ? () => _confirmReplacePending(loco)
                     : null,
                 onTransferAllocations: widget.selectionMode &&