experiment(PodcastPlayerView): add ShareLink button to full player for sharing episode URL

Marks/Views/PodcastPlayerView.swift

@@ -467,6 +467,14 @@ struct PodcastPlayerView: View {
                     .background(Color(.systemGray5))
                     .clipShape(Capsule())
             }
+
+            if let url = URL(string: articleUrl) {
+                ShareLink(item: url, subject: Text(vm.currentArticleTitle.isEmpty ? "Marks Podcast" : vm.currentArticleTitle)) {
+                    Label("Share Episode", systemImage: "square.and.arrow.up")
+                        .font(.system(size: 14, weight: .medium))
+                        .foregroundStyle(.secondary)
+                }
+            }
         }
     }