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

lib/components/pages/new_entry/new_entry_submit_logic.dart

@@ -128,7 +128,9 @@ extension _NewEntrySubmitLogic on _NewEntryPageState {
       );
       _lastSubmittedSnapshot = snapshot;
       _activeDraftId = null;
-    } catch (e) {
+    } catch (e, st) {
+      debugPrint('Leg submit/update failed: $e');
+      debugPrintStack(stackTrace: st);
       if (!mounted) return;
       messenger?.showSnackBar(
         SnackBar(content: Text('Failed to submit: $e')),

lib/components/pages/new_entry/new_entry_traction_logic.dart

@@ -73,6 +73,8 @@ extension _NewEntryTractionLogic on _NewEntryPageState {
     for (var i = 0; i < _tractionItems.length; i++) {
       final item = _tractionItems[i];
       if (item.isMarker || item.loco == null) continue;
+      final locoId = item.loco!.id;
+      if (locoId == 0) continue;
       int allocPos;
       if (i > markerIndex) {
         allocPos = -(i - markerIndex);
@@ -80,8 +82,7 @@ extension _NewEntryTractionLogic on _NewEntryPageState {
         allocPos = (markerIndex - 1) - i;
       }
       payload.add({
-        "loco_type": item.loco!.type,
-        "loco_number": item.loco!.number,
+        "loco_id": locoId,
         "alloc_pos": allocPos,
         "alloc_powering": item.powering ? 1 : 0,
       });