adds ability to star chats

ios/Packages/Sybil/Sources/Sybil/SybilSidebarView.swift

@@ -160,6 +160,14 @@ struct SybilSidebarItemList: View {
                             }
                             .buttonStyle(.plain)
                             .contextMenu {
+                                Button {
+                                    Task {
+                                        await viewModel.setItemStarred(item.selection, starred: !item.starred)
+                                    }
+                                } label: {
+                                    Label(item.starred ? "Unstar" : "Star", systemImage: item.starred ? "star.slash" : "star")
+                                }
+
                                 if item.kind == .chat {
                                     Button {
                                         renameTarget = item
@@ -245,6 +253,12 @@ struct SybilSidebarRow: View {
                     .lineLimit(1)
                     .layoutPriority(1)
 
+                if item.starred {
+                    Image(systemName: "star.fill")
+                        .font(.system(size: 10, weight: .semibold))
+                        .foregroundStyle(.yellow)
+                }
+
                 Spacer(minLength: 8)
 
                 if item.isRunning {