feat: add URL input button to control toolbar

Sources/MiniPlayerApp.swift

@@ -293,6 +293,7 @@ struct ControlToolbar: View {
             // 按钮行 — 紧凑布局
             HStack(spacing: 4) {
                 TB(icon: "folder") { bridge.openFileDialog(); onTouch() }
+                TB(icon: "link") { bridge.showURLDialog = true; onTouch() }
                 TB(icon: "backward.fill") { bridge.playPrev(); onTouch() }
                 TB(icon: bridge.isPlaying ? "pause.fill" : "play.fill") { bridge.togglePlayPause(); onTouch() }
                 TB(icon: "forward.fill") { bridge.playNext(); onTouch() }