Improve entries page and latest changes panel, units on events and timeline

lib/components/pages/loco_timeline.dart

@@ -36,6 +36,21 @@ class _LocoTimelinePageState extends State<LocoTimelinePage> {
     WidgetsBinding.instance.addPostFrameCallback((_) => _load());
   }
 
+  dynamic _normalizeFieldValue(_FieldEntry field) {
+    final name = field.field.name.toLowerCase();
+    final val = field.value;
+    if (name == 'max_speed') {
+      final numVal = val is num ? val.toDouble() : double.tryParse('$val');
+      if (numVal == null) return val;
+      final unit = (field.unit ?? 'kph').toLowerCase();
+      if (unit == 'mph') {
+        return numVal * 1.60934;
+      }
+      return numVal;
+    }
+    return val;
+  }
+
   @override
   void dispose() {
     _disposeDrafts(_draftEvents);
@@ -57,7 +72,7 @@ class _LocoTimelinePageState extends State<LocoTimelinePage> {
   String? _eventDateForEntry(LocoAttrVersion entry) {
     final masked = entry.maskedValidFrom?.trim();
     if (masked != null && masked.isNotEmpty) return masked;
-    final from = entry.validFrom ?? entry.txnFrom;
+    final from = entry.validFrom;
     if (from == null) return null;
     return DateFormat('yyyy-MM-dd').format(from);
   }
@@ -115,7 +130,8 @@ class _LocoTimelinePageState extends State<LocoTimelinePage> {
     draft.details = '';
     draft.fields.add(
       _FieldEntry(field: field)
-        ..value = _valueForEntry(entry),
+        ..value = _valueForEntry(entry)
+        ..unit = _guessUnit(field, entry.valueLabel),
     );
 
     setState(() {
@@ -123,6 +139,16 @@ class _LocoTimelinePageState extends State<LocoTimelinePage> {
     });
   }
 
+  String? _guessUnit(EventField field, String valueLabel) {
+    final name = field.name.toLowerCase();
+    if (name == 'max_speed') {
+      final val = valueLabel.toLowerCase();
+      if (val.contains('mph')) return 'mph';
+      return 'kph';
+    }
+    return _defaultUnitForField(field);
+  }
+
   Future<void> _deleteEntry(LocoAttrVersion entry) async {
     if (_isDeleting) return;
     final blockId = entry.versionId;
@@ -241,7 +267,7 @@ class _LocoTimelinePageState extends State<LocoTimelinePage> {
             invalid.add('Field ${field.field.display} is empty');
             break;
           }
-          values[field.field.name] = val;
+          values[field.field.name] = _normalizeFieldValue(field);
         }
         if (invalid.isNotEmpty) continue;
         if (values.isEmpty) {