feat: space opus

Closes #833

Signed-off-by: bggRGjQaUbCoE <githubaccount56556@proton.me>

lib/common/skeleton/space_opus.dart

@@ -0,0 +1,48 @@
+import 'package:PiliPlus/common/skeleton/skeleton.dart';
+import 'package:PiliPlus/utils/utils.dart';
+import 'package:flutter/material.dart';
+
+class SpaceOpusSkeleton extends StatelessWidget {
+  const SpaceOpusSkeleton({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final surface = Theme.of(context).colorScheme.onInverseSurface;
+    return Skeleton(
+      child: Card(
+        clipBehavior: Clip.hardEdge,
+        margin: EdgeInsets.zero,
+        shape: const RoundedRectangleBorder(
+          borderRadius: BorderRadius.all(Radius.circular(6)),
+        ),
+        child: LayoutBuilder(
+          builder: (context, constraints) {
+            return Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Container(
+                  height: (0.68 + 0.82 * Utils.random.nextDouble()) *
+                      constraints.maxWidth,
+                  color: surface,
+                ),
+                Container(
+                  height: 10,
+                  color: surface,
+                  margin: const EdgeInsets.all(10),
+                  width: constraints.maxWidth * 0.7,
+                ),
+                Container(
+                  height: 10,
+                  color: surface,
+                  margin:
+                      const EdgeInsets.only(left: 10, right: 10, bottom: 10),
+                  width: constraints.maxWidth,
+                ),
+              ],
+            );
+          },
+        ),
+      ),
+    );
+  }
+}