feat: add frontend app, improve static file serving with lazy loading and root redirect

frontend/lib/widgets/run_status_badge.dart

@@ -0,0 +1,47 @@
+import 'package:flutter/material.dart';
+import '../api/models.dart';
+
+class RunStatusBadge extends StatelessWidget {
+  final RunStatus status;
+
+  const RunStatusBadge({super.key, required this.status});
+
+  Color _color(BuildContext context) {
+    switch (status) {
+      case RunStatus.pending:
+        return Colors.amber;
+      case RunStatus.running:
+        return Colors.blue;
+      case RunStatus.completed:
+        return Colors.green;
+      case RunStatus.error:
+        return Colors.red;
+    }
+  }
+
+  IconData _icon() {
+    switch (status) {
+      case RunStatus.pending:
+        return Icons.schedule;
+      case RunStatus.running:
+        return Icons.play_circle_outline;
+      case RunStatus.completed:
+        return Icons.check_circle;
+      case RunStatus.error:
+        return Icons.error;
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final c = _color(context);
+    return Chip(
+      avatar: Icon(_icon(), size: 16, color: c),
+      label: Text(
+        status.name.toUpperCase(),
+        style: TextStyle(color: c, fontWeight: FontWeight.bold, fontSize: 12),
+      ),
+      backgroundColor: c.withValues(alpha: 0.1),
+    );
+  }
+}