fix(runtime): bound resources and quarantine stalled extensions

test/ttl_cache_test.dart

@@ -0,0 +1,37 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:spotiflac_android/utils/ttl_cache.dart';
+
+void main() {
+  test('TtlCache evicts the least recently used entry at its bound', () {
+    final cache = TtlCache<int>(const Duration(minutes: 1), maxEntries: 2);
+
+    cache.set('first', 1);
+    cache.set('second', 2);
+    expect(cache.get('first'), 1);
+    cache.set('third', 3);
+
+    expect(cache.get('first'), 1);
+    expect(cache.get('second'), isNull);
+    expect(cache.get('third'), 3);
+    expect(cache.length, 2);
+  });
+
+  test('TtlCache sweeps expired keys even when another key is accessed', () {
+    final cache = TtlCache<int>(Duration.zero, maxEntries: 3);
+    cache.set('expired', 1);
+
+    expect(cache.get('different-key'), isNull);
+    expect(cache.length, 0);
+  });
+
+  test('TtlCache rejects a non-positive bound', () {
+    expect(
+      () => TtlCache<int>(const Duration(minutes: 1), maxEntries: 0),
+      throwsArgumentError,
+    );
+    expect(
+      () => TtlCache<int>(const Duration(minutes: 1), maxEntries: -1),
+      throwsArgumentError,
+    );
+  });
+}