Onstart sync progressbar: init

lib/widgets/sync_progress_overlay.dart

@@ -0,0 +1,60 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+import '../connector/meshcore_connector.dart';
+
+class SyncProgressAppBarBottom extends StatelessWidget
+    implements PreferredSizeWidget {
+  static const double height = 3;
+
+  const SyncProgressAppBarBottom({super.key});
+
+  @override
+  Size get preferredSize => const Size.fromHeight(height);
+
+  @override
+  Widget build(BuildContext context) {
+    return Consumer<MeshCoreConnector>(
+      builder: (context, connector, _) {
+        final state = _SyncProgressState.fromConnector(connector);
+        if (state == null) return const SizedBox(height: height);
+
+        return SizedBox(
+          height: height,
+          child: LinearProgressIndicator(
+            value: state.value,
+            minHeight: height,
+            color: state.color,
+            backgroundColor: state.color.withValues(alpha: 0.18),
+          ),
+        );
+      },
+    );
+  }
+}
+
+class _SyncProgressState {
+  final double? value;
+  final Color color;
+
+  const _SyncProgressState({required this.value, required this.color});
+
+  static _SyncProgressState? fromConnector(MeshCoreConnector connector) {
+    if (connector.isLoadingContacts) {
+      return _SyncProgressState(
+        value: connector.contactSyncProgress,
+        color: Colors.red,
+      );
+    }
+    if (connector.isSyncingChannels) {
+      return _SyncProgressState(
+        value: connector.channelSyncProgress / 100,
+        color: Colors.blue,
+      );
+    }
+    if (connector.isShowingQueuedMessageSyncProgress) {
+      return const _SyncProgressState(value: null, color: Colors.green);
+    }
+    return null;
+  }
+}